Exposure apparatus, exposure method, and method for producing device

ABSTRACT

An exposure apparatus exposes a substrate by projecting an image of a predetermined pattern through a liquid onto the substrate. The exposure apparatus includes a projection optical system which projects the image of the pattern onto the substrate, a liquid supply mechanism which has a supply flow passage through which the liquid is supplied onto the substrate, and a liquid recovery mechanism which has a recovery flow passage through which the supplied liquid is recovered. At least one of the supply flow passage and the recovery flow passage is formed in a stacked member in which a plurality of plate members are stacked.

CROSS-REFERENCE

This is a Division of U.S. patent application Ser. No. 11/211,749 filedAug. 26, 2005, which is now U.S. Pat. No. 7,268,854 which in turn is aContinuation of International Application No. PCT/JP2004/002295 filedFeb. 26, 2004 claiming the conventional priority of Japanese patentApplication Nos. 2003-049365 filed on Feb. 26, 2003; 2003-110748 filedon Apr. 15, 2003; and 2003-320100 filed on Sep. 11, 2003. Thedisclosures of these applications are incorporated by reference hereinin their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an exposure apparatus, an exposuremethod, and a method for producing a device in which a substrate isexposed with a pattern in a state that a liquid immersion-area is formedbetween a projection optical system and the substrate.

2. Description of the Related Art

Semiconductor devices and liquid crystal display devices are produced bythe so-called photolithography technique in which a pattern formed on amask is transferred onto a photosensitive substrate. The exposureapparatus, which is used in the photolithography step, includes a maskstage for supporting the mask and a substrate stage for supporting thesubstrate. The pattern on the mask is transferred onto the substrate viaa projection optical system while successively moving the mask stage andthe substrate stage. In recent years, it is demanded to realize thehigher resolution of the projection optical system in order to respondto the further advance of the higher integration of the device pattern.As the exposure wavelength to be used is shorter, the resolution of theprojection optical system becomes higher. As the numerical aperture ofthe projection optical system is larger, the resolution of theprojection optical system becomes higher. Therefore, the exposurewavelength, which is used for the exposure apparatus, is shortened yearby year, and the numerical aperture of the projection optical system isincreased as well. The exposure wavelength, which is dominantly used atpresent, is 248 nm of the KrF excimer laser. However, the exposurewavelength of 193 nm of the ArF excimer laser, which is shorter than theabove, is also practically used in some situations. When the exposure isperformed, the depth of focus (DOF) is also important in the same manneras the resolution. The resolution R and the depth of focus δ arerepresented by the following expressions respectively.R=k ₁ ·λ/NA  (1)δ=±k ₂ ·λ/NA ²  (2)

In the expressions, λ represents the exposure wavelength, NA representsthe numerical aperture of the projection optical system, and k₁ and k₂represent the process coefficients. According to the expressions (1) and(2), the following fact is appreciated. That is, when the exposurewavelength λ is shortened and the numerical aperture NA is increased inorder to enhance the resolution R, then the depth of focus δ isnarrowed.

If the depth of focus δ is too narrowed, it is difficult to match thesubstrate surface with respect to the image plane of the projectionoptical system. It is feared that the margin is insufficient during theexposure operation. Accordingly, the liquid immersion method has beensuggested, which is disclosed, for example, in International PublicationNo. 99/49504 as a method for substantially shortening the exposurewavelength and widening the depth of focus. In this liquid immersionmethod, the space between the lower surface of the projection opticalsystem and the substrate surface is filled with a liquid such as wateror any organic solvent to form a liquid immersion area so that theresolution is improved and the depth of focus is magnified about n timesby utilizing the fact that the wavelength of the exposure light beam inthe liquid is 1/n as compared with that in the air (n represents therefractive index of the liquid, which is about 1.2 to 1.6 in ordinarycases).

The conventional technique as described above involves the followingproblems. The conventional technique is effective because the liquidimmersion area can be formed between the projection optical system andthe substrate when the scanning exposure is performed while moving thesubstrate in a predetermined direction. However, the conventionaltechnique is constructed such that the liquid is supplied at a positionin front of the projection area onto which the image of the pattern ofthe mask is to be projected. The conventional technique is constructedsuch that the liquid is allowed to flow in one direction along with themovement direction of the substrate from the position in front of theprojection area. Further, the conventional technique is constructed suchthat the position (nozzle), from which the liquid is supplied, is alsoswitched when the movement direction of the substrate is switched fromthe predetermined direction to the opposite direction. However, when theswitching operation is performed, then the supply of the liquid in onedirection is suddenly stopped with respect to the projection area, andthe supply of the liquid in another direction is started. Therefore, thefollowing fact has been progressively elucidated. That is, a problemarises in some cases such that the vibration of the liquid (so-calledthe water hammer phenomenon) is generated between the projection opticalsystem and the substrate, and the vibration is generated in the liquidsupply unit itself (for example, the supply tube and the nozzle). As aresult, the deterioration of the pattern image is caused. Further, aproblem also arises in other cases such that the liquid immersion areais not formed sufficiently between the projection optical system and thesubstrate because of the construction in which the liquid is allowed toflow in one direction with respect to the projection area.

The conventional technique as described above also involves thefollowing problem. That is, the liquid cannot be recovered sufficientlyin some cases because the recovery unit for recovering the liquid isconstructed such that the liquid is recovered on only the downstreamside of the liquid allowed to flow in the movement direction of thesubstrate. If the liquid cannot be recovered sufficiently, it is fearedthat the liquid may remain on the substrate, and any exposure unevennessmay be caused by the remaining liquid. If the liquid cannot be recoveredsufficiently, an inconvenience also arises, for example, such that theremaining liquid is scattered to surrounding mechanical parts, and anyrust appears. Further, if the liquid remains and/or the liquid isscattered, then the environment (for example, the humidity), in whichthe substrate is placed, is varied or fluctuated. It is also feared thatany desired pattern transfer accuracy cannot be obtained, for example,due to the occurrence of the change of the refractive index on theoptical path for the detecting light beam of the optical interferometerto be used to measure the stage position.

When the liquid is recovered from the substrate by using a liquidrecovery nozzle, there is such a possibility that the vibration isgenerated in the liquid recovery unit itself (for example, the recoverytube and the nozzle). If the vibration is transmitted, for example, tothe projection optical system, the substrate stage, and/or the opticalmember of the interferometer for measuring the position of the substratestage, it is feared that the circuit pattern cannot be formed accuratelyon the substrate.

SUMMARY OF THE INVENTION

The present invention has been made taking the foregoing circumstancesinto consideration, an object of which is to provide an exposureapparatus, an exposure method, and a method for producing a device, inwhich a liquid immersion area can be stably formed, the liquid can besatisfactorily recovered, and the exposure process can be performedaccurately while avoiding, for example, the outflow and the scatteringof the liquid to the surroundings when the exposure process is performedin a state in which the liquid immersion area is formed between aprojection optical system and a substrate. Another object of the presentinvention is to provide an exposure apparatus and a method for producinga device, in which the exposure process can be performed accuratelywithout being affected by the variation generated during the supply orthe recovery of the liquid when the exposure process is performed in astate in which a liquid immersion area is formed between a projectionoptical system and a substrate.

In order to achieve the objects as described above, the presentinvention adopts the following constructions.

According to a first aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a predetermined pattern through a liquid onto the substrate, theexposure apparatus comprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate; and    -   a liquid supply mechanism which supplies the liquid onto the        substrate simultaneously from a plurality of positions which are        apart, in a plurality of different directions, from a projection        area of the projection optical system to form a liquid immersion        area on a part of the substrate including the projection area.

According to the present invention, the liquid supply mechanism, whichis provided to form the liquid immersion area, simultaneously suppliesthe liquid at the plurality of positions which are apart, in theplurality of different directions, from the projection area (i.e., froma plurality of different sides of the projection area, for example, fromat least two sides of the X side, the −X side, the +Y side, and the −Yside in the case of a rectangular projection area). Therefore, thedesired liquid immersion area can be formed between the projectionoptical system and the substrate. Further, when the exposure process isperformed while moving the substrate, the liquid immersion area can bealways formed satisfactorily even when the movement direction of thesubstrate is changed, because the liquid is supplied simultaneously fromthe plurality of positions which are apart in the plurality ofdirections. When the liquid is simultaneously supplied on the both sidesof the projection area, it is unnecessary to switch the supply positionof the liquid. Therefore, it is possible to avoid the occurrence of thevibration of the liquid (water hammer phenomenon), and it is possible toaccurately project the pattern image onto the substrate.

According to a second aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a predetermined pattern through a liquid onto the substrate, theexposure apparatus comprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate;    -   a liquid supply mechanism which supplies the liquid onto the        substrate to form a liquid immersion area on a part of the        substrate including a projection area of the projection optical        system; and    -   a liquid recovery mechanism which recovers the liquid from the        substrate simultaneously at a plurality of positions apart from        the projection area in a plurality of different directions.

According to the present invention, the liquid recovery mechanism, whichis provided to recover the liquid, simultaneously recovers the liquid atthe plurality of positions apart from the projection area in theplurality of different directions (i.e., from a plurality of differentsides of the projection area, for example, from at least two sides ofthe X side, the −X side, the +Y side, and the −Y side in the case of arectangular projection area). Accordingly, the liquid can be recoveredreliably. Therefore, it is possible to avoid the occurrence of a statein which the liquid remains on the substrate, it is possible to avoidthe occurrence of any uneven exposure and the variation of theenvironment in which the substrate is placed, and it is possible toaccurately project the pattern image onto the substrate.

According to a third aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a predetermined pattern through a liquid onto the substrate, theexposure apparatus comprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate;    -   a liquid supply mechanism which supplies the liquid onto the        substrate to form a liquid immersion area on a part of the        substrate including a projection-area of the projection optical        system; and    -   a liquid recovery mechanism which recovers the liquid from the        substrate simultaneously at a plurality of positions, wherein:    -   the liquid recovery mechanism recovers the liquid with a        recovery force which differs depending on the position for        recovering the liquid.

According to the present invention, the liquid recovery mechanism, whichrecovers the liquid simultaneously at the plurality of positions on thesubstrate, recovers the liquid with the recovery force that differsdepending on the position for recovering the liquid. Accordingly, it ispossible to smoothly perform the operation for recovering the liquid.Therefore, the space between the projection optical system and thesubstrate can be filled with an appropriate amount of the liquid, and itis possible to form the liquid immersion area in the desired area on thesubstrate. For example, when the recovery force for the liquid, which isused on the front side (downstream side) in relation to the movement(scanning) direction of the substrate, is set to be larger than therecovery force on the back side (upstream side), it is possible tosmoothly perform the operation for recovering the liquid. Alternatively,it is possible to smoothly perform the operation for recovering theliquid as well, when the liquid recovery mechanism, which is arranged ata position disposed in the movement (scanning) direction of thesubstrate, has the recovery force for the liquid which is larger thanthe recovery force for the liquid of the liquid recovery mechanismarranged at a position disposed in a direction intersecting the movementdirection.

According to a fourth aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a predetermined pattern through a liquid onto the substrate, theexposure apparatus comprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate;    -   a liquid supply mechanism which supplies the liquid onto the        substrate to form a liquid immersion area on a part of the        substrate including a projection area of the projection optical        system;    -   a liquid recovery mechanism which recovers the liquid on the        substrate at a liquid recovery position apart from the        projection area; and    -   a trap member which is arranged outside the liquid recovery        position of the liquid by the liquid recovery mechanism with        respect to the projection area and which is formed with a liquid        trap surface for capturing the liquid.

According to the present invention, the trap member, which is formedwith the liquid trap surface having a predetermined length to capturethe liquid, is provided outside the liquid recovery position of theliquid recovery mechanism. Accordingly, even if the liquid isunsuccessfully recovered by the liquid recovery mechanism, then theliquid is trapped by the trap member, and thus it is possible to avoidthe occurrence of the inconvenience such as the scattering and theoutflow of the liquid to the surroundings. Therefore, it is possible toavoid the occurrence of the variation of the environment in which thesubstrate is placed. It is possible to project the pattern image ontothe substrate at a desired pattern accuracy.

According to a fifth aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a predetermined pattern through a liquid onto the substrate, theexposure apparatus comprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate;    -   a liquid supply mechanism which supplies the liquid onto the        substrate to form a liquid immersion area on a part of the        substrate including a projection area of the projection optical        system; and    -   a liquid recovery mechanism which recovers the liquid from the        substrate at a liquid recovery position apart from the        projection area, wherein:    -   the liquid supply mechanism supplies the liquid between the        projection area and the liquid recovery position of the liquid        recovery mechanism.

According to the present invention, the liquid is supplied by the liquidsupply mechanism between the projection area and the liquid recoveryposition of the liquid recovery mechanism. Therefore, the liquid issmoothly supplied to the projection area. Further, the supplied liquidcan be smoothly recovered from the substrate.

According to a sixth aspect of the present invention, there is providedan exposure method for exposing a substrate by projecting an image of apredetermined pattern through a liquid onto the substrate by using aprojection optical system, the exposure method comprising:

-   -   supplying the liquid onto a part of the substrate including a        projection area of the projection optical system to form a        liquid immersion area, the liquid having an affinity for a        liquid contact surface disposed at an end of the projection        optical system, and the affinity being higher than an affinity        for a surface of the substrate; and    -   projecting the image of the predetermined pattern onto the        substrate through the liquid supplied to the liquid immersion        area.

According to the present invention, the liquid can be allowed to maketight contact with the liquid contact surface disposed at the forwardend of the projection optical system. It is possible to provide a stableliquid immersion state for the optical path between the projectionoptical system and the substrate. Further, it is possible to smoothlyrecover the liquid on the substrate.

A method for producing a device according to the present inventioncomprises using the exposure apparatus or the exposure method accordingto the aspect as described above. According to the present invention, itis possible to provide the device which has a pattern formed at asatisfactory pattern accuracy and which is capable of exhibiting desiredperformance.

According to a seventh aspect of the present invention, there isprovided an exposure apparatus which exposes a substrate by projectingan image of a predetermined pattern through a liquid onto the substrate,the exposure apparatus comprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate;    -   a liquid supply mechanism which has a supply flow passage        through which the liquid is supplied onto the substrate; and    -   a liquid recovery mechanism which has a recovery flow passage        through which the supplied liquid is recovered, wherein:    -   at least one of the supply flow passage and the recovery flow        passage is formed in a stacked member in which a plurality of        plate members are stacked.

It is necessary for the liquid immersion exposure that the uniformliquid flow is supplied to the liquid immersion area, and the liquid isrecovered therefrom. The stacked member, which is provided for theexposure apparatus of the present invention, can be formed by stacking aplurality of plate members formed with the flow passages respectively sothat the flow passages are communicated with each other to form at leastone of the supply flow passage and the recovery flow passagerespectively. Therefore, even when the flow passage structure iscomplicated, the flow passages can be formed extremely compactly andeasily at low cost.

According to an eighth aspect of the present invention, there isprovided an exposure apparatus which exposes a substrate by projectingan image of a predetermined pattern through a liquid onto the substrate,the exposure apparatus comprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate; and    -   a liquid supply mechanism which supplies the liquid onto the        substrate to form a liquid immersion area on a part of the        substrate including a projection area of the projection optical        system, wherein:    -   the liquid supply mechanism is isolated from the projection        optical system in terms of vibration.

According to the exposure apparatus concerning the eighth aspect, theprojection optical system and the liquid supply mechanism are isolatedfrom each other in terms of the vibration. That is, even when anyvibration is generated in the liquid supply mechanism, the vibration isnot transmitted to the projection optical system. Therefore, it ispossible to avoid the occurrence of an inconvenience which would beotherwise caused such that the pattern image is deteriorated by thevibration of the projection optical system. It is possible to accuratelyproject the pattern image onto the substrate.

The exposure apparatus may further comprise a first support member whichsupports the projection optical system, and a second support-memberwhich is isolated from the first support member in terms of vibrationand which supports the liquid supply mechanism. According to thisstructure, the first support member for supporting the projectionoptical system and the second support member for supporting the liquidsupply mechanism are isolated from each other in terms of the vibration.Therefore, the vibration, which is generated in the liquid supplymechanism, is not transmitted to the projection optical system. Further,for example, when the exposure apparatus is constructed such that aninterferometer for measuring the position information about thesubstrate stage is attached to the first support member, and/or areference mirror (fixed mirror) is attached to the barrel of theprojection optical system, then the vibration is not transmitted to theinterferometer and the reference mirror. Therefore, it is possible toaccurately perform the measurement of the position information about thesubstrate stage and the position control based on the result of themeasurement.

According to a ninth aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a predetermined pattern through a liquid onto the substrate, theexposure apparatus comprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate; and    -   a liquid recovery mechanism which recovers the liquid supplied        onto a part of the substrate including a projection area of the        projection optical system, wherein:    -   the liquid recovery mechanism is isolated from the projection        optical system in terms of vibration.

According to the exposure apparatus concerning the ninth aspect, theprojection optical system and the liquid recovery mechanism are isolatedfrom each other in terms of the vibration. Accordingly, even when anyvibration is generated in the liquid recovery mechanism, the vibrationis not transmitted to the projection optical system. Therefore, it ispossible to avoid the occurrence of an inconvenience which would beotherwise caused such that the pattern image is deteriorated by thevibration of the projection optical system. It is possible to accuratelyproject the pattern image onto the substrate.

The exposure apparatus concerning the ninth aspect may further comprisea first support member which supports the projection optical system, anda second support member which is isolated from the first support memberin terms of vibration and which supports the liquid recovery mechanism.According to this structure, the first support member for supporting theprojection optical system and the second support member for supportingthe liquid recovery mechanism are isolated from each other in terms ofthe vibration. Therefore, the vibration, which is generated in theliquid recovery mechanism, is not transmitted to the projection opticalsystem. Further, for example, when the exposure apparatus is constructedsuch that an interferometer for measuring the position information aboutthe substrate stage is attached to the first support member, and/or areference mirror (fixed mirror) is attached to the barrel of theprojection optical system, then the vibration is not transmitted to theinterferometer and the reference mirror. Therefore, it is possible toaccurately perform the measurement of the position information about thesubstrate stage and the position control based on the result of themeasurement.

According to a tenth aspect of the present invention, there is providedan exposure apparatus which successively exposes a plurality of shotareas on a substrate by projecting an image of a predetermined patternthrough a liquid onto the substrate , the exposure apparatus comprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate; and    -   a liquid supply mechanism which supplies the liquid from a        supply port arranged opposite to the substrate to form a liquid        immersion area on a part of the substrate including a projection        area of the projection optical system, wherein:    -   the liquid supply mechanism continuously supplies the liquid        from the supply port during a period in which an exposure        process is performed for the plurality of shot areas on the        substrate.

According to the exposure apparatus concerning the tenth aspect of thepresent invention, the liquid is continuously supplied from the supplyport arranged at the predetermined position irrelevant to the movementdirection of the substrate during the period in which the exposureprocess is performed for the plurality of shot areas on the substrate.Therefore, it is possible to avoid the vibration of the liquid supplymechanism itself and the vibration of the liquid (water hammerphenomenon). It is possible to accurately project the pattern image ontothe substrate.

According to an eleventh aspect of the present invention, there isprovided an exposure apparatus which successively exposes a plurality ofshot areas on a substrate by projecting an image of a predeterminedpattern through a liquid onto the substrate, the exposure apparatuscomprising:

-   -   a projection optical system which projects the image of the        pattern onto the substrate;    -   a liquid supply mechanism which supplies the liquid from a        supply port arranged at a predetermined position to form a        liquid immersion area on a part of the substrate including a        projection area of the projection optical system; and    -   a liquid recovery mechanism which has a recovery port arranged        to be opposed to the substrate and which recovers the liquid        supplied from the liquid supply mechanism, wherein:    -   the liquid recovery mechanism continuously recovers the liquid        through the recovery port during a period in which an exposure        process is performed for the plurality of shot areas on the        substrate.

According to the exposure apparatus concerning the eleventh aspect ofthe present invention, the liquid is continuously recovered through therecovery port irrelevant to the movement direction of the substrateduring the period in which the exposure process is performed for theplurality of shot areas on the substrate. Accordingly, it is possible torecover the liquid more reliably. It is possible to suppress thevibration of the liquid recovery mechanism itself caused upon the startand the stop of the recovery. It is possible to accurately project thepattern image onto the substrate.

A method for producing a device according to the present inventioncomprises using the exposure apparatus according to the aspect asdescribed above. According to the present invention, it is possible toprovide the device which has a pattern formed at a satisfactory patternaccuracy and which is capable of exhibiting desired performance.

According to the present invention, the exposure process can beperformed accurately even when the exposure process is performed in thestate in which the liquid immersion area is formed between theprojection optical system and the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic arrangement illustrating an embodiment of anexposure apparatus of the present invention.

FIG. 2 shows a plan view illustrating a schematic arrangement of aliquid supply mechanism and a liquid recovery mechanism ascharacteristic features of the present invention.

FIG. 3 shows a perspective view illustrating a schematic arrangement ofthe liquid supply mechanism and the liquid recovery mechanism as thecharacteristic features of the present invention.

FIG. 4 shows a side sectional view illustrating a schematic arrangementof the liquid supply mechanism and the liquid recovery mechanism as thecharacteristic features of the present invention.

FIG. 5 shows shot areas established on a substrate.

FIGS. 6A and 6B schematically show the behavior of the liquid.

FIG. 7 shows another embodiment of a liquid supply mechanism and aliquid supply mechanism.

FIG. 8 shows still another embodiment of a liquid supply mechanism and aliquid supply mechanism.

FIG. 9 shows still another embodiment of a liquid supply mechanism and aliquid supply mechanism.

FIGS. 10A and 10B show still another embodiment of a liquid supplymechanism.

FIG. 11 shows a side sectional view illustrating another embodiment of atrap member.

FIG. 12 shows a side sectional view illustrating still anotherembodiment of a trap member.

FIG. 13 shows a side sectional view illustrating still anotherembodiment of a trap member.

FIG. 14 shows a schematic perspective view illustrating still anotherembodiment of a liquid supply mechanism and a liquid recovery mechanismaccording to the present invention.

FIG. 15 shows another embodiment of a slit tube section as illustratedin FIG. 14.

FIG. 16 shows a schematic perspective view illustrating still anotherembodiment of a liquid supply mechanism and a liquid recovery mechanismaccording to the present invention.

FIG. 17 shows a perspective view illustrating a first member of a flowpassage-forming member.

FIGS. 18A and 18B show perspective views illustrating a second member ofthe flow passage-forming member.

FIGS. 19A and 19B show perspective views illustrating a third member ofthe flow passage-forming member.

FIG. 20 shows a schematic arrangement illustrating another embodiment ofan exposure apparatus according to the present invention.

FIG. 21 shows a flow chart illustrating exemplary steps of producing asemiconductor device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

An explanation will be made below about the exposure apparatus accordingto the present invention with reference to the drawings. FIG. 1 shows aschematic arrangement illustrating an embodiment of the exposureapparatus of the present invention. With reference to FIG. 1, anexposure apparatus EX includes a mask stage MST which supports a mask M,a substrate stage PST which supports a substrate P, an illuminationoptical system IL which illuminates, with an exposure light beam EL, themask M supported by the mask stage MST, a projection optical system PLwhich performs projection exposure for the substrate P supported by thesubstrate stage PST with an image of a pattern of the mask M illuminatedwith the exposure light beam EL, and a control unit CONT whichcollectively controls the overall operation of the exposure apparatusEX.

The exposure apparatus EX of this embodiment is a liquid immersionexposure apparatus to which the liquid immersion method is applied inorder that the exposure wavelength is substantially shortened to improvethe resolution and the depth of focus is substantially widened. Theexposure apparatus EX includes a liquid supply mechanism 10 whichsupplies the liquid 1 onto the substrate P, and a liquid recoverymechanism 20 which recovers the liquid 1 from the substrate P. Theexposure apparatus EX forms a liquid immersion area AR2 on a part of thesubstrate P including a projection area AR1 of the projection opticalsystem PL by the liquid 1 supplied from the liquid supply mechanism 10at least during the period in which the pattern image of the mask M istransferred onto the substrate P. Specifically, the exposure apparatusEX is operated as follows. That is, the space between the surface of thesubstrate P and the optical element 2 disposed at the end portion of theprojection optical system PL is filled with the liquid 1. The patternimage of the mask M is projected onto the substrate P to expose thesubstrate P therewith via the projection optical system PL and throughthe liquid 1 disposed between the projection optical system PL and thesubstrate P.

The embodiment of the present invention will now be explained asexemplified by a case of the use of the scanning type exposure apparatus(so-called scanning stepper) as the exposure apparatus EX in which thesubstrate P is exposed with the pattern formed on the mask M whilesynchronously moving the mask M and the substrate P in mutuallydifferent directions (opposite directions) in the scanning directions.In the following explanation, the Z axis direction is the directionwhich is coincident with the optical axis AX of the projection opticalsystem PL, the X axis direction is the synchronous movement direction(scanning direction) for the mask M and the substrate P in the planeperpendicular to the Z axis direction, and the Y axis direction is thedirection (non-scanning direction) perpendicular to the Z axis directionand the Y axis direction. The directions about the X axis, the Y axis,and the Z axis are designated as θx, θY, and θz directions respectively.The term “substrate” referred to herein includes substrates obtained bycoating a semiconductor wafer surface with a photoresist as aphotosensitive material, and the term “mask” includes a reticle formedwith a device pattern to be subjected to the reduction projection ontothe substrate.

The illumination optical system IL is used so that the mask M, which issupported on the mask stage MST, is illuminated with the exposure lightbeam EL. The illumination optical system IL includes, for example, anexposure light source, an optical integrator which uniformizes theilluminance of the light flux radiated from the exposure light source, acondenser lens which collects the exposure light beam EL come from theoptical integrator, a relay lens system, and a variable field diaphragmwhich sets the illumination area on the mask M illuminated with theexposure light beam EL to be slit-shaped. The predetermined illuminationarea on the mask M is illuminated with the exposure light beam EL havinga uniform illuminance distribution by the illumination optical systemIL. Those usable as the exposure light beam EL radiated from theillumination optical system IL include, for example, emission lines(g-ray, h-ray, i-ray) in the ultraviolet region radiated, for example,from a mercury lamp, far ultraviolet light beams (DUV light beams) suchas the KrF excimer laser beam (wavelength: 248 nm), and vacuumultraviolet light beams (VUV light beams) such as the ArF excimer laserbeam (wavelength: 193 nm) and the F₂ laser beam (wavelength: 157 nm). Inthis embodiment, the ArF excimer laser beam is used.

The mask stage MST supports the mask M. The mask stage MST istwo-dimensionally movable in the plane perpendicular to the optical axisAX of the projection optical system PL, i.e., in the XY plane, and it isfinely rotatable in the θZ direction. The mask stage MST is driven by amask stage-driving unit MSTD such as a linear motor. The maskstage-driving unit MSTD is controlled by the control unit CONT. Amovement mirror 50 is provided on the mask stage MST. A laserinterferometer 51 is provided at a position opposed to the movementmirror 50. The position in the two-dimensional direction and the angleof rotation of the mask M on the mask stage MST are measured inreal-time by the laser interferometer 51. The result of the measurementis outputted to the control unit CONT. The control unit CONT drives themask stage-driving unit MSTD on the basis of the result of themeasurement obtained by the laser interferometer 51 to thereby positionthe mask M supported on the mask stage MST.

The projection optical system PL projects the pattern on the mask M ontothe substrate P at a predetermined projection magnification β to performthe exposure. The projection optical system PL includes a plurality ofoptical elements including the optical element (lens) 2 provided at theend portion on the side of the substrate P. The optical elements aresupported by a barrel PK. In this embodiment, the projection opticalsystem PL is based on the reduction system having the projectionmagnification β which is, for example, 1/4 or 1/5. The projectionoptical system PL may be any one of the 1× magnification system and themagnifying system. The optical element 2, which is disposed at the endportion of the projection optical system PL of this embodiment, isprovided detachably (exchangeably) with respect to the barrel PK. Theliquid 1 in the liquid immersion area AR2 makes contact with the opticalelement 2.

The optical element 2 is formed of fluorite. Fluorite has a highaffinity for water. Therefore, the liquid 1 is successfully allowed tomake tight contact with substantially the entire surface of the liquidcontact surface 2 a of the optical element 2. That is, in thisembodiment, the liquid (water) 1, which has the high affinity for theliquid contact surface 2 a of the optical element 2, is supplied.Therefore, the highly tight contact is effected between the liquid 1 andthe liquid contact surface 2 a of the optical element 2. The opticalpath between the optical element 2 and the substrate P can be reliablyfilled with the liquid 1. The optical element 2 may be formed of quartzhaving a high affinity for water. A water-attracting (lyophilic orliquid-attracting) treatment may be applied to the liquid contactsurface 2 a of the optical element 2 to further enhance the affinity forthe liquid 1.

The substrate stage PST supports the substrate P. The substrate stagePST includes a Z stage 52 which holds the substrate P by the aid of asubstrate holder, an XY stage 53 which supports the Z stage 52, and abase 54 which supports the XY stage 53. The substrate stage PST isdriven by a substrate stage-driving unit PSTD such as a linear motor.The substrate stage-driving unit PSTD is controlled by the control unitCONT. When the Z stage 52 is driven, the substrate P, which is held onthe Z stage 52, is subjected to the control of the position (focusposition) in the Z axis direction and the positions in the θX and θYdirections. When the XY stage 53 is driven, the substrate P is subjectedto the control of the position in the XY directions (position in thedirections substantially parallel to the image plane of the projectionoptical system PL). That is, the Z stage 52 controls the focus positionand the angle of inclination of the substrate P so that the surface ofthe substrate P is adjusted to match the image plane of the projectionoptical system PL in the auto-focus manner and the auto-leveling manner.The XY stage 53 positions the substrate P in the X axis direction andthe Y axis direction. It goes without saying that the Z stage and the XYstage may be provided as an integrated body.

A movement mirror 55, which is movable together with the substrate stagePST with respect to the projection optical system PL, is provided on thesubstrate stage PST (Z stage 52). A laser interferometer 56 is providedat a position opposed to the movement mirror 55. The angle of rotationand the position in the two-dimensional direction of the substrate P onthe substrate stage PST are measured in real-time by the laserinterferometer 56. The result of the measurement is outputted to thecontrol unit CONT. The control unit CONT drives the substratestage-driving unit PSTD on the basis of the result of the measurement ofthe laser interferometer 56 to thereby position the substrate Psupported on the substrate stage PST.

An auxiliary plate 57 is provided on the substrate stage PST (Z stage52) so that the substrate P is surrounded thereby. The auxiliary plate57 has a flat surface which has approximately the same height as that ofthe surface of the substrate P held by the substrate holder. In thisarrangement, a gap of about 0.1 to 2 mm is provided between theauxiliary plate 57 and the edge of the substrate P. However, the liquid1 scarcely flows into the gap owing to the surface tension of the liquid1. Even when the vicinity of the circumferential edge of the substrate Pis subjected to the exposure, the liquid 1 can be retained under theprojection optical system PL by the aid of the auxiliary plate 57.

The liquid supply mechanism 10 supplies the predetermined liquid 1 ontothe substrate P. The liquid supply mechanism 10 includes a first liquidsupply unit 11 and a second liquid supply unit 12 which are capable ofsupplying the liquid 1, a first supply member 13 which is connected tothe first liquid supply unit 11 through a supply tube 11A having a flowpassage and which has a supply port 13A for supplying, onto thesubstrate P, the liquid 1 fed from the first liquid supply unit 11, anda second supply member 14 which is connected to the second liquid supplyunit 12 through a supply tube 12A having a flow passage and which has asupply port 14A for supplying, onto the substrate P, the liquid 1 fedfrom the second liquid supply unit 12. The first and second supplymembers 13, 14 are arranged closely to the surface of the substrate P,and they are provided at positions which are different from each otherin the surface direction of the substrate P. Specifically, the firstsupply member 13 of the liquid supply mechanism 10 is provided on oneside (−X side) in the scanning direction with respect to the projectionarea AR1, and the second supply member 14 is provided on the other side(+X side).

Each of the first and second liquid supply units 11, 12 includes, forexample, a tank for accommodating the liquid 1, a pressurizing pump, andthe like. The first and second liquid supply units 11, 12 supply theliquid 1 onto the substrate P through the supply tubes 11A, 12A and thesupply members 13, 14 respectively. The operation of the first andsecond liquid supply units 11, 12 for supplying the liquid is controlledby the control unit CONT. The control unit CONT is capable ofcontrolling the liquid supply amounts per unit time onto the substrate Pby the first and second liquid supply units 11, 12 independentlyrespectively.

In this embodiment, pure water is used for the liquid 1. Those capableof being transmitted through pure water include the ArF excimer laserbeam as well as the emission line (g-ray, h-ray, i-ray) in theultraviolet region radiated, for example, from a mercury lamp and thefar ultraviolet light beam (DUV light beam) such as the KrF excimerlaser beam (wavelength: 248 nm).

The liquid recovery mechanism 20 recovers the liquid 1 from the surfaceof the substrate P. The liquid recovery mechanism 20 includes a recoverymember 22 which has a recovery port 22A arranged closely to the surfaceof the substrate P, and a liquid recovery unit 21 which is connected tothe recovery member 22 through a recovery tube 21A having a flowpassage. The liquid recovery unit 21 includes, for example, a suckingunit such as a vacuum pump, a tank for accommodating the recoveredliquid 1, and the like. The liquid recovery unit 21 recovers the liquid1 from the surface of the substrate P via the recovery member 22 and therecovery tube 21A. The operation of the liquid recovery unit 21 forrecovering the liquid is controlled by the control unit CONT. Thecontrol unit CONT is capable of controlling the liquid recovery amountper unit time by the liquid recovery unit 21.

A trap member 30, which is formed with a liquid trap surface 31 having apredetermined length to capture the liquid 1, is arranged outside therecovery member 22 of the liquid recovery mechanism 20.

FIG. 2 shows a plan view illustrating a schematic arrangement of theliquid supply mechanism 10 and the liquid recovery mechanism 20, andFIG. 3 shows a perspective view with partially broken illustration. Asshown in FIG. 2, the projection area AR1 of the projection opticalsystem PL is designed to have a rectangular shape in which the Y axisdirection (non-scanning direction) is the longitudinal direction. Theliquid immersion area AR2, which is filled with the liquid 1, is formedon a part of the substrate P so that the projection area AR1 is coveredthereby. The first supply member 13 of the liquid supply mechanism 10,which is used to form the liquid immersion area AR2 of the projectionarea AR1, is provided on one side (−X side) in the scanning directionwith respect to the projection area AR1, and the second supply member 14is provided on the other side (+X side).

As shown in FIGS. 2 and 3, the first and second supply members 13, 14have internal spaces (internal flow passages) 13H, 14H for allowing theliquid 1 fed from the first and second liquid supply units 11, 12 toflow therethrough, and supply ports 13A, 14A for supplying, onto thesubstrate P, the liquid 1 having flown through the internal spaces 13H,14H respectively. Although the second liquid supply unit 12 is not shownin FIG. 3, the structure thereof is the same as that of the first liquidsupply unit 11. Each of the supply ports 13A, 14A of the first andsecond supply members 13, 14 is formed to be substantially circulararc-shaped as viewed in the plan view. The size of the supply port 13A,14A in the Y axis direction is designed to be larger than at least thesize of the projection area AR1 in the Y axis direction. The supplyports 13A, 14A, which are formed to be substantially circular arc-shapedas viewed in the plan view, are arranged to interpose the projectionarea AR1 in relation to the scanning direction (X direction). The liquidsupply mechanism 10 simultaneously supplies the liquid 1 from aplurality of positions which are apart, in a plurality of differentdirections, from the projection area AR1 through the supply ports 13A,14A, i.e., on different sides of the rectangular projection area AR1(from the both sides (from the side in the +X direction and the side inthe −X direction) in this embodiment) of the projection area AR1.

The recovery member 22 of the liquid recovery mechanism 20 is adual-structured annular member having a recovery port 22A which isformed annularly and continuously so that the recovery port 22A isdirected to the surface of the substrate P, and an annular internalspace (internal flow passage) 22H which allows the liquid 1 recoveredthrough the recovery port 22A to flow therethrough. The recovery member22 of the liquid recovery mechanism 20 is arranged to surround theprojection area AR1 and the supply members 13, 14 of the liquid recoverymechanism 10. Partition members (partitions) 23, which divide theinternal space 22H into a plurality of spaces (divided spaces) 24 in thecircumferential direction, are provided at predetermined intervals inthe recovery member 22. That is, the partition members 23 are providedat the inside of the recovery port 22A which is formed continuously tosurround the projection area AR1. The respective divided spaces 24,which are divided by the partition members 23, make penetration in thevertical direction. The lower end of the recovery member 22 having therecovery port 22A is disposed closely to the surface of the substrate P.On the other hand, the upper end is a manifold 25 as a collected spacefor spatially collecting the plurality of divided spaces 24. One end ofthe recovery tube 21A is connected to the manifold 25, and the other endis connected to the liquid recovery unit 21. The liquid recoverymechanism 20 recovers the liquid 1 from the substrate P by the aid ofthe recovery port 22A (recovery member 22) and the recovery tube 21A bydriving the liquid recovery unit 21. That is, the position ofinstallation of the recovery port 22A is the recovery position forrecovering the liquid 1 from the substrate P. The liquid recoverymechanism 20 recovers the liquid 1 from the substrate P at the recoveryposition apart from the projection area AR1. In this embodiment, therecovery port 22A of the liquid recovery mechanism 20 is substantiallycircular and annular as viewed in the plan view, which is constructed tosurround the projection area AR1. That is, the recovery port 22A existson the four sides of the rectangular projection area AR1 (on the side inthe +X direction, the side in the −X direction, the side in the +Ydirection, and the side in the −Y direction), i.e., at the fourpositions which are apart in the four directions perpendicular to theprojection area AR1. Therefore, the liquid recovery mechanism 20 cansimultaneously recover the liquid 1 from the substrate P at theplurality of positions which are apart, in the plurality of differentdirections, from the projection area AR1 by using the recovery port 22Aprovided to surround the projection area AR1.

The positions of installation of the respective supply ports 13A, 14A ofthe first and second supply members 13, 14 of the liquid supplymechanism 10, i.e., the positions to supply the liquid 1 onto thesubstrate P are disposed between the liquid recovery positions(positions of the recovery port 22A) and the projection area AR1. Inother words, the liquid 1 is supplied by the liquid supply mechanism 10between the projection area AR1 and the liquid recovery positions of theliquid recovery mechanism 20.

FIG. 4 shows a magnified side sectional view illustrating major parts todepict the first and second supply members 13, 14 and the recoverymember 22 arranged closely to the substrate P. As shown in FIG. 4, therespective internal flow passages 13H, 14H of the first and secondsupply members 13, 14 of the liquid supply mechanism 10 are providedsubstantially perpendicularly to the surface of the substrate P.Similarly, the internal flow passage 22H (divided space 24) of therecovery member 22 of the liquid recovery mechanism 20 is also providedsubstantially perpendicularly to the surface of the substrate P. Thesupply positions of the liquid 1 supplied by the first and second supplymembers 13, 14 to the substrate P (positions of installation of thesupply ports 13A, 14A) are set between the liquid recovery position ofthe liquid recovery mechanism 20 (position of installation of therecovery port 22A) and the projection area AR1. The projection opticalsystem PL and the respective first and second supply members 13, 14 areprovided while being separated from each other by predetermineddistances. The recovery member 22 and the respective first and secondsupply members 13, 14 are provided while being separated from each otherby predetermined distances as well. In this embodiment, the distancebetween the surface of the substrate P and the supply port 13A, 14A, thedistance between the surface of the substrate P and the recovery port22A, and the distance between the surface of the substrate P and thelower end surface of the projection optical system PL are set to beapproximately identical to one another. In other words, the positions(heights) in the Z direction are set to be identical for the supplyports 13A, 14A, the recovery port 22A, and the lower end surface of theprojection optical system PL respectively.

The liquid 1, which is supplied from the supply ports 13A, 14A of thefirst and second supply members 13, 14 to the substrate P in thedirection substantially perpendicular to the substrate surface, is fedso that the liquid 1 is spread while causing the wetting between thesubstrate P and the lower end surface of the end portion (opticalelement 2) of the projection optical system PL. Further, the liquid 1,which outflows to the outside of the supply members 13, 14 with respectto the projection area AR1, is recovered (sucked) in the directionsubstantially perpendicular to the substrate surface from the recoveryport 22A of the recovery member 22 which is arranged outside the supplymembers 13, 14 with respect to the projection area AR1.

In this embodiment, at least the members for allowing the liquid 1 toflow therein, which are included in the respective members forconstructing the liquid supply mechanism 10 and the liquid recoverymechanism 20, are formed of, for example, synthetic resin such aspolytetrafluoroethylene. Accordingly, it is possible to suppress thecontamination of the liquid 1 with any impurity.

The trap member 30, which is formed with the liquid trap surface 31having predetermined lengths to capture the liquid 1 unsuccessfullyrecovered by the recovery member 22 of the liquid recovery mechanism 20,is provided outside the recovery member 22 of the liquid recoverymechanism 20 in relation to the projection area AR1. The trap member 30is attached to the outer side surface of the recovery member 22. Thetrap surface 31 is the surface (i.e., the lower surface) of the trapmember 30 directed toward the substrate P. The trap surface 31 isinclined with respect to the horizontal plane as shown in FIG. 4.Specifically, the trap surface 31 is inclined to make separation fromthe surface of the substrate P (to be directed upwardly) at outerpositions with respect to the projection area AR1 (liquid immersion areaAR2). The trap member 30 is formed of, for example, metal such asstainless steel.

As shown in FIG. 2, the trap member 30 is an annular member as viewed inthe plan view. The trap member 30 is connected to the outer side surfaceof the recovery member 22 so that the trap member 30 is fitted to therecovery member 22. The trap-surface 31 of the trap member 30 isarranged to surround the projection area AR1 (liquid immersion areaAR2). In this embodiment, the trap member 30 and the trap surface 31 asthe lower surface thereof are substantially elliptical as viewed in theplan view. That is, the trap surface 31 of the trap member 30 isprovided such that the length in the radial direction differs dependingon the position on the basis of the optical axis AX of the projectionoptical system PL. In this embodiment, the length of the trap surface 31in the scanning direction (X axis direction) is longer than that in thenon-scanning direction (Y axis direction). More specifically, the lengthof the trap surface 31 is the longest at the position corresponding tothe center of the projection area AR1 in the Y axis direction.

A lyophilic or liquid-attracting treatment (water-attracting treatment)is applied to the trap surface 31 to enhance the affinity for the liquid1. In this embodiment, the liquid 1 is water. Therefore, the surfacetreatment, which is in conformity with the affinity for water, isapplied to the trap surface 31. The surface of the substrate P is coatedwith a water-repelling (with a contact angle of about 70 to 80°)photosensitive material (for example, TARF-P6100 produced by TOKYO OHKAKOGYO CO., LTD.) for the ArF excimer laser. The liquid affinity of thetrap surface 31 for the liquid 1 is higher than the liquid affinity ofthe surface of the substrate P for the liquid 1.

The surface treatment for the trap surface 31 is performed depending onthe polarity of the liquid 1. In this embodiment, the liquid 1 is waterhaving large polarity. Therefore, as for the liquid-attracting treatmentfor the trap surface 31, a thin film is formed with a substance such asalcohol having a molecular structure with large polarity. Accordingly,the liquid-attracting property or hydrophilicity is given to the trapsurface 31. Alternatively, the water-attracting property orhydrophilicity can be also given to the trap surface 31 by applying anO₂ plasma treatment in which the plasma treatment is performed by using,for example, oxygen (O₂) gas as the treatment gas. As described above,when water is used as the liquid 1, it is desirable to adopt such atreatment that substance having the molecular structure with the largepolarity such as the OH group is arranged on the trap surface 31. Inthis case, the thin film for the surface treatment is formed of amaterial which is insoluble in the liquid 1. The treatment condition ofthe liquid-attracting treatment is appropriately changed depending onthe material characteristic of the liquid 1 to be used.

Next, an explanation will be made about a method for exposing thesubstrate P with the pattern image of the mask M by using theexposure-apparatus EX described above.

In this embodiment, the exposure apparatus EX performs the projectionexposure for the pattern image of the mask M onto the substrate P whilemoving the mask M and the substrate P in the X axis direction (scanningdirection). During the scanning exposure, a part of the pattern image ofthe mask M is projected onto the rectangular projection area AR1disposed just under the end portion of the projection optical system PL.The mask M is moved at the velocity V in the −X direction (or in the +Xdirection) with respect to the projection optical system PL, insynchronization with which the substrate P is moved at the velocity β·V(β represents the projection magnification) in the +X direction (or inthe −X direction) by the aid of the XY stage 53. As shown in a plan viewof FIG. 5, a plurality of shot areas S1 to S12 are set on the substrateP. After the exposure is completed for one shot area, the next shot areais moved to the scanning start position in accordance with the steppingmovement of the substrate P. The scanning exposure process issuccessively performed thereafter for the respective shot areas whilemoving the substrate P in the step-and-scan manner. In this embodiment,the control unit CONT moves the XY stage 53 while monitoring the outputof the laser interferometer 56 so that the optical axis AX of theprojection optical system PL is advanced along broken line arrows 58 asshown in FIG. 5.

At first, the mask M is loaded on the mask stage MST, and the substrateP is loaded on the substrate stage PST (see FIG. 1). Subsequently, whenthe scanning exposure process is performed, the control unit CONT drivesthe liquid supply mechanism 10 to start the operation to supply theliquid onto the substrate P. The liquid 1, which is supplied from thefirst and second liquid supply units 11, 12 of the liquid supplymechanism 10 respectively in order to form the liquid immersion areaAR2, flows through the supply tubes 11A, 12A, and then the liquid 1 issupplied onto the substrate P via the first and second supply members13, 14 to form the liquid immersion area AR2 between the projectionoptical system PL and the substrate P. In this embodiment, as shown inFIG. 4, the liquid 1, which has flown through the supply tubes 11A, 12A,is spread in the widthwise directions of the internal flow passages 13H,14H of the supply members 13, 14. The liquid 1 is supplied to wideranges on the substrate P from the supply ports 13A, 14A. In thisarrangement, the supply ports 13A, 14A are arranged on the both sides ofthe projection area AR1 in the X axis direction (scanning direction).The control unit CONT simultaneously supplies the liquid 1 onto thesubstrate P from the both sides of the projection area AR1 through thesupply ports 13A, 14A of the liquid supply mechanism 10.

The liquid supply mechanism 10 simultaneously supplies the liquid 1 fromthe supply ports 13A, 14A provided on the both sides of the projectionarea AR1, i.e., from the plurality of positions which are apart, in theplurality of different directions (+X direction, −X direction), from theprojection area AR1. Accordingly, the liquid 1, which is supplied ontothe substrate P from the supply ports 13A, 14A, forms the liquidimmersion area AR2 in a range which is wider than at least theprojection area AR1.

In this embodiment, when the liquid 1 is supplied to the substrate Pfrom the both sides of the projection area AR1 in the scanningdirection, the control unit CONT controls the operation of the first andsecond liquid supply units 11, 12 of the liquid supply mechanism 10 tosupply the liquid so that the supply amount per unit time of the liquidsupplied from the place in front of the projection area AR1 in relationto the scanning direction is set to be larger than the supply amount ofthe liquid supplied from the place on the opposite side. For example,when the exposure process is performed while moving the substrate P inthe +X direction, the control unit CONT is operated such that the amountof the liquid supplied from the −X side with respect to the projectionarea AR1 (i.e., from the supply port 13A) is larger than the amount ofthe liquid supplied from the +X side (i.e., from the supply port 14A).On the other hand, when the exposure process is performed while movingthe substrate P in the −X direction, the amount of the liquid suppliedfrom the +X side with respect to the projection area AR1 is larger thanthe amount of the liquid supplied from the −X side.

The control unit CONT drives the liquid recovery unit 21 of the liquidrecovery mechanism 20 to perform the operation to recover the liquid onthe substrate P concurrent with the operation to supply the liquid 1 bythe liquid supply mechanism 10. Accordingly, as shown in FIG. 4, theliquid 1 on the substrate P, which flows to the outside of the supplyports 13A, 14A with respect to the projection area AR1, is recoveredfrom the recovery port 22A. The liquid 1, which has been recovered fromthe recovery port 22A, passes through the divided spaces 24 comparted bythe partition members 23 respectively, and then the liquid 1 iscollected to the manifold 25. The liquid 1, which has been collected tothe manifold 25, passes through the recovery tube 21A, and the liquid 1is recovered by the liquid recovery unit 21. As described above, thisembodiment is provided with the structure in which the plurality ofdivided spaces 24 are connected to the one liquid recovery unit 21. Theliquid recovery mechanism 20 simultaneously recovers the liquid 1 fromthe substrate P through the recovery port 22A provided to surround theprojection area AR1 from the plurality of positions which are apart, inthe plurality of different directions, from the projection area AR1,i.e., from the four sides of the rectangular projection area AR1 (fromthe side in the +X direction, the side in the −X direction, the side inthe +Y direction, and the side in the −Y direction).

The control unit CONT operates the liquid supply mechanism 10 and theliquid recovery mechanism 20 to recover the liquid 1 from the substrateP concurrently with the supply of the liquid 1 to the surface of thesubstrate P, while the pattern image of the mask M is projected onto thesubstrate P to perform the exposure via the projection optical system PLand the liquid 1 disposed between the projection optical system PL andthe substrate P, while moving, in the X axis direction (scanningdirection), the substrate stage PST which supports the substrate P.During this process, the liquid supply mechanism 10 simultaneouslysupplies the liquid 1 through the supply ports 13A, 14A from the bothsides of the projection area AR1 in relation to the scanning direction.Therefore, the liquid immersion area AR2 is formed uniformly andsatisfactorily. Further, the liquid recovery mechanism 20 simultaneouslyrecovers the liquid 1 at the plurality of positions around theprojection area AR1 including the both sides of the projection area AR1in the scanning direction through the recovery port 22A of the recoverymember 22 which surrounds the projection area AR1. Therefore, the liquid1 is prevented from the scattering and the outflow to the surroundingsof the substrate P. In this embodiment, pure water, which has the lowaffinity for the photosensitive material on the surface of the substrateP, is supplied as the liquid 1. Therefore, it is possible to smoothlyperform the recovery by the liquid recovery mechanism 20.

FIG. 6A schematically shows the behavior of the liquid 1 when theexposure process is performed for the first shot area (for example, S1,S3, etc. shown in FIG. 5) set on the substrate P while moving thesubstrate P in the +X direction. With reference to FIG. 6A, the liquid 1is simultaneously supplied from the supply ports 13A, 14A to the spacebetween the projection optical system PL and the substrate P.Accordingly, the liquid immersion area AR2 is formed to include theprojection area AR1. In this procedure, the amount of the liquid 1supplied per unit time from the supply port 13A provided on the −X sidewith respect to the projection area AR1 is set to be larger than theamount of the liquid supplied per unit time from the supply port 14Aprovided on the +X side. Therefore, the liquid 1, which is supplied fromthe supply port 13A, is smoothly arranged in the space between theprojection optical system PL and the substrate P as if the liquid 1 ispulled by the substrate P moving in the +X direction. The liquid 1,which intends to outflow to the outside of the supply ports 13A, 14A, isrecovered from the recovery port 22A to suppress the occurrence of anyinconvenience which would be otherwise caused such that the liquid 1outflows to the surroundings of the substrate P.

In such a situation, when the substrate P is moved in the +X direction,then the amount of the liquid moved toward the +X side with respect tothe projection area AR is increased, and the recovery port 22A, whichhas the liquid recovery position disposed on the +X side, cannot recoverall of the liquid 1 in some cases. However, as shown in FIG. 6A, theliquid 1, which is unsuccessfully recovered by the recovery port 22A onthe +X side, is captured by the trap surface 31 of the trap member 30provided on the +X side with respect to the liquid recovery position.Therefore, the liquid 1 does not cause the scattering and the outflow,for example, to the surroundings of the substrate P. In this embodiment,the trap surface 31 is subjected to the liquid-attracting treatment forthe liquid 1, and the trap surface 31 has the affinity for the liquidhigher than that of the surface of the substrate P. Therefore, theliquid 1, which intends to outflow to the outside of the liquid recoveryposition of the recovery port 22A, is not pulled toward the substrate Pbut is pulled toward the trap surface 31. Accordingly, the occurrence ofany inconvenience is suppressed, which would be otherwise caused forexample, such that the liquid 1 remains on the substrate P.

In this embodiment, the trap surface 31 is inclined in the upwarddirection at the outer positions on the basis of the liquid immersionarea AR2 including the projection area AR1. Therefore, it is possible toavoid the outflow of the liquid 1 to the outside more effectively. Inother words, owing to the inclination in the upward direction, thesecond volume of the space between the substrate P and the trap surface31 is larger than the first volume of the space between the substrate Pand the projection optical system PL (volume corresponding to the unitarea of the substrate P). Therefore, the liquid 1, which intends tooutflow, is smoothly retained by the portion of the second volume.Further, owing to the inclination in the upward direction, the fluidenergy, which urges the outflow to the outside, is converted into thepotential energy as a result of the movement in the upward directionalong the trap surface 31. Accordingly, it is possible to effectivelyavoid the outflow of the liquid 1 to the outside.

The amount of the liquid supplied from the supply port 14A provided onthe +X side is set to be smaller than the amount of the liquid suppliedfrom the supply port 13A provided on the −X side. That is, the amount ofthe liquid supplied from the supply port 14A disposed at the positionnearer to the recovery port 22A on the +X side as compared with thesupply port 13A is set to be small. Therefore, even when the liquid 1 ispulled by the substrate P which is moved toward the +X side, the amountof the liquid of the outflow to the outside from the +X side of thesubstrate P is suppressed.

When the exposure process is completed for the first shot area, thecontrol unit CONT causes the stepping movement of the substrate P inorder that the projection area AR1 of the projection optical system PLis arranged on the second shot area which is different from the firstshot area. Specifically, the control unit CONT causes the steppingmovement in the Y axis direction between the two shot areas S1, S2 onthe substrate P, for example, in order to perform the scanning exposureprocess for the shot area S2 after the completion of the scanningexposure process for the shot area S1. In this procedure, the liquidsupply mechanism 10 is operated such that the supply amount of theliquid 1 during the stepping movement between the two shot areas on thesubstrate P is different from the supply amount during the exposure forthe shot area. Specifically, the control unit CONT is operated such thatthe supply amount of the liquid supplied per unit time from the liquidsupply mechanism 10 onto the substrate P during the stepping movement issmaller than the supply amount of the liquid supplied during thescanning exposure for the shot area. Accordingly, it is possible tosuppress the supply amount of the liquid supplied to the substrate Pduring the stepping movement which does not contribute to the exposureprocess. It is possible to suppress the amount of use of the liquid inthe entire exposure process (until the substrate P is unloaded from thesubstrate stage PST after the substrate P has been loaded on thesubstrate stage PST and the exposure process has been completed for allof the shot areas S1 to S12). As described above, the control unit CONTchanges the liquid supply amount per unit time of each of the first andsecond liquid supply units 11, 12 depending on the movement operationfor the substrate P (stepping movement or scanning movement) whichconstitutes a part of the executing operation of the exposure process.

In this embodiment, the liquid supply mechanism 10 reduces the supplyamount per unit time of the liquid 1 during the stepping movement of thesubstrate P, but the operation to supply the liquid 1 is maintained(continued). In other words, the liquid supply mechanism 10 maintains(continues) the operation to supply the liquid from the supply ports13A, 14A even when the scanning direction is changed due to the changeof the shot area and even when the stepping movement is performed. Asdescribed above, when the plurality of shot areas on the substrate P aresuccessively subjected to the exposure, the liquid supply mechanism 10continuously supplies the liquid 1 from the supply ports 13A, 14Aprovided at the plurality of positions, while the liquid supply positionis not changed depending on the scanning direction, and the liquidsupply position is not changed during the stepping movement. In otherwords, the liquid supply mechanism 10 continuously supplies the liquid 1from the plurality of positions until a series of the exposure processoperation is completed in relation to one substrate P (until thesubstrate P is unloaded from the substrate stage PST after the substrateP has been loaded on the substrate stage PST and the exposure processhas been completed for all of the shot areas S1 to S12). Accordingly, itis possible to avoid the occurrence of the vibration of the liquid(water hammer phenomenon) which would be otherwise caused by the supplyand the stop of the liquid 1.

FIG. 6B schematically shows the behavior of the liquid 1 when theexposure process is performed for the second shot area (for example, S2,S4, etc. shown in FIG. 5) set on the substrate P while moving thesubstrate P in the −X direction. With reference to FIG. 6B, the liquid 1is supplied from the supply ports 13A, 14A to the space between theprojection optical system PL and the substrate P. Accordingly, theliquid immersion area AR2 is formed to include the projection area AR1.In this procedure, the amount of the liquid 1 supplied per unit timefrom the supply port 14A provided on the +X side with respect to theprojection area AR1 is set to be larger than the amount of the liquid 1supplied per unit time from the supply port 13A provided on the −X side.Therefore, the liquid 1, which is supplied from the supply port 14A issmoothly arranged in the space between the projection optical system PLand the substrate P as if the liquid 1 is pulled by the substrate Pmoving in the −X direction. As described above, the control unit CONTchanges the liquid supply amount per unit time of each of the first andsecond liquid supply units 11, 12 depending on the movement direction(movement operation) for the substrate P which constitutes a part of theexecuting operation of the exposure process. The liquid 1, which intendsto outflow to the outside of the supply ports 13A, 14A, is recoveredfrom the recovery port 22A to suppress the occurrence of anyinconvenience which would be otherwise caused such that the liquid 1outflows to the surroundings of the substrate P.

In such a situation, when the substrate P is moved in the −X direction,then the liquid 1, which is captured by the trap surface 31 on the +Xside, is moved downwardly along the trap surface 31, and the liquid 1 isrecovered from the recovery port 22A of the liquid recovery mechanism20. Accordingly, it is possible to reliably avoid the remaining and theoutflow of the liquid 1 to the outside. The amount of the liquid movedtoward the −X side is increased as the substrate P is moved toward the−X side. Accordingly, even when all of the liquid 1 is unsuccessfullyrecovered by the recovery port 22A on the −X side, the liquid 1 iscaptured by the trap surface 31 of the trap member 30 provided on the −Xside from the liquid recovery position as shown in FIG. 6B.

In this embodiment, the trap surface 31 is formed so that the trapsurface 31 is inclined in the upward direction at the outer positionswith respect to the projection area AR1. However, the trap surface 31may be horizontal (0 degree). On the other hand, if the trap surface 31is inclined in the downward direction, the fluid energy, which intendsto outflow to the outside, is not converted into the potential energy.Further, when the substrate P is moved in the opposite direction aswell, the fluid 1 is not moved to the recovery port 22A to make downwardmovement along the trap surface 31. For this reason, it is impossible tosmoothly recover the liquid 1 from the recovery port 22A. Therefore, itis preferable that the trap surface 31 is a horizontal surface (0degree) or an inclined surface directed in the upward direction.

When the liquid supply amount per unit time to be supplied onto thesubstrate P is large, and/or when the scanning velocity is high, thenthe liquid amount to outflow to the outside is increased as well.Therefore, the angle of inclination of the trap surface 31 is designedto be a most appropriate angle depending on the liquid supply amount andthe scanning velocity. In other words, when the liquid supply amount islarge and/or when the scanning velocity is high, then the angle ofinclination of the trap surface 31 is set to be large. On the otherhand, if the angle of inclination of the trap surface 31 is too large,the liquid 1 cannot be captured (retained) sufficiently by the trapsurface 31 in some cases. In such a situation, the liquid-retainingforce of the trap surface 31 is increased by enhancing theliquid-attracting property brought about by the liquid-attractingtreatment. Therefore, when the angle of inclination is increased, thetreatment condition of the liquid-attracting treatment is changed togive the most appropriate liquid-attracting property to the trap surface31. Accordingly, even when the angle of inclination is increased, it ispossible to retain the liquid 1. Thus, the angle of inclination of thetrap surface 31 is set to be the optimum angle on the basis of therespective parameters including, for example, the liquid supply amount,the scanning velocity, and the material characteristic of the liquid(liquid-attracting property of the trap surface).

The recovery member 22 of this embodiment is constructed to possess therecovery port 22A which is formed continuously to have the annularshape, the partition members 23 which are provided in the recovery port22A, and the plurality of divided spaces 24 which are divided by thepartition members 23, wherein the liquid recovery unit 21 is connectedvia the recovery tube 21A to the manifold 25 to which the plurality ofdivided spaces 24 are collected. Accordingly, it is enough that oneliquid recovery unit 21 is provided, which is constructed whileincluding the vacuum pump and the like. Therefore, the arrangement ofthe apparatus can be simplified. In some situations, the suction load,which is exerted to recover the liquid 1, may differ among therespective positions of the recovery member 22 in the circumferentialdirection. In such a state, the suction force of the liquid recoveryunit 21 may be lowered, and it is impossible to smoothly perform therecovery operation. However, the provision of the partition members 23makes it possible to smoothly perform the recovery operation. That is,for example, the following state may be sometimes caused due to thebehavior the liquid 1. Only the liquid 1 is recovered (sucked) from therecovery port 22A on the +X side of the recovery member 22, while theliquid 1 with the air (mixed with the air) is sucked from the recoveryport 22A on the −X side. In such a situation, the air-mixed area isspread in the recovery port 22A on the −X side, and the followinginconvenience may arise. That is, when the liquid 1 is recovered by theliquid recovery unit 21 provided as one line as in this embodiment, themixed air lowers the suction force of the vacuum pump which constitutesthe liquid recovery unit 21. However, the area, in which only the liquid1 is sucked, can be spatially separated from the air-mixed area byproviding the mutually independent divided spaces 24 by providing thepartition members 23 at the interior (in the internal space 22H) of therecovery port 22A which is continuously formed. Therefore, it ispossible to avoid the occurrence of any inconvenience which would beotherwise caused such that the air-mixed area is spread and/or thesuction force of the liquid recovery unit 21 is lowered by the mixedair. Accordingly, the liquid recovery mechanism 20 can smoothly recoverthe liquid 1 even when the liquid recovery unit 21 is provided as oneline.

As explained above, the liquid supply mechanism 10 is provided, whichsimultaneously supplies the liquid 1 onto the substrate P at theplurality of positions which are apart, in the plurality of differentdirections, from the projection area AR1 (from the plurality of mutuallydifferent sides of the projection area AR1) in order to form the liquidimmersion area AR2. Therefore, even when the substrate P is moved in theplurality of directions including the scanning direction (±X directions)and the stepping direction (±Y directions), the liquid immersion areaAR2 can be always formed smoothly and satisfactorily between theprojection optical system PL and the substrate P. Therefore, theexposure process can be performed at the high resolution and the widedepth of focus.

The liquid 1 is continuously supplied from the plurality of positions bythe liquid supply mechanism 10 when the plurality of shot areas on thesubstrate P are successively subjected to the exposure processrespectively. Therefore, it is possible to avoid the occurrence of theliquid vibration (water hammer phenomenon) which would be otherwisecaused by the supply and the stop of the liquid 1. Thus, it is possibleto avoid the deterioration of the pattern to be transferred.

The liquid supply mechanism 10 supplies the liquid 1 from the both sidesof the projection area AR1 in the scanning direction through the supplyports 13A, 14A. Therefore, the supplied liquid 1 is spread while causingthe wetting over the projection area AR1 as if the liquid 1 is pulled bythe substrate P moving in the scanning direction. Therefore, the liquidimmersion area AR2 is smoothly formed to include the projection areaAR1. In this embodiment, the liquid supply mechanism 10 is operated suchthat the amount of the liquid supplied from the position in front of theprojection area AR1 in relation to the scanning direction is larger thanthe amount of the liquid supplied from the position on the oppositeside. Therefore, the liquid 1, which is supplied onto the substrate P,flows in the movement direction of the substrate P as if the liquid 1 ispulled by the moving substrate P. The liquid 1 is smoothly arranged asif the liquid 1 is attracted and introduced into the space between theprojection optical system PL and the substrate P. Therefore, the liquid1, which is supplied from the liquid supply mechanism 10, is smoothlyarranged between the projection optical system PL and the substrate Peven when the supply energy thereof is small. It is possible to form theliquid immersion area AR2 satisfactorily. The direction of the flow ofthe liquid 1 can be switched by changing the amount of the liquidsupplied from the supply ports 13A, 14A respectively depending on thescanning direction. Accordingly, the liquid immersion area AR2 can besmoothly formed between the projection optical system PL and thesubstrate P even when the substrate F is subjected to the scanning inany one of the directions of the +X direction and the −X direction.Thus, it is possible to obtain the high resolution and the wide depth offocus.

The recovery member 22 of the liquid recovery mechanism 20 is formedcircularly and annularly to surround the projection area AR1 and thesupply members 13, 14. The liquid 1 is simultaneously recovered from thesurface of the substrate P at the plurality of positions (from theplurality of different sides of the projection area AR1) which areapart, in the plurality of different directions, from the projectionarea AR1. Therefore, it is possible to reliably avoid the occurrence ofthe inconvenience including, for example, the scattering and the outflowof the liquid 1 to the outside of the substrate P. That is, the liquidrecovery mechanism 20 continuously performs the recovery operation fromthe recovery port 22A arranged to surround the projection area AR1 untila series of the exposure process operation is completed for onesubstrate P (until the liquid 1, which has formed the liquid immersionarea AR2, is completely recovered after the exposure process has beencompleted for all of the shot areas S1 to S12 on the substrate P).Therefore, even when the liquid 1 is spread while causing the wetting inany direction during the operation of the series of the exposure processfor the substrate P, the liquid 1 can be recovered in a well-suitedmanner. Further, it is unnecessary to stop the suction of the liquidthrough the recovery port 22 during the operation of the series of theexposure process in relation to the substrate P. Therefore, it ispossible to suppress the vibration caused by the stop of the suction ofthe liquid.

The apparatus is provided with the trap member 30 for capturing theliquid 1 unsuccessfully recovered by the liquid recovery mechanism 20.Accordingly, it is possible to avoid the occurrence of the inconvenienceincluding, for example, the scattering and the outflow of the liquid 1to the outside of the substrate P. In this embodiment, the trap surface31 is formed to have the elliptical shape as viewed in the plan view, inwhich the longitudinal direction extends in the scanning direction (Xaxis direction) in which the liquid 1 is most likely to outflow to theoutside of the substrate P. Therefore, it is possible to reliably avoidthe outflow of the liquid 1 to the outside. The liquid-attractingtreatment is applied to the trap surface 31 to enhance the affinity forthe liquid 1. Therefore, it is possible to satisfactorily capture theliquid 1 which intends to outflow. Further, the surface treatment isapplied so that the affinity of the trap surface 31 for the liquid ishigher than the affinity of the surface of the substrate P for theliquid. Therefore, the liquid 1, which intends to outflow to theoutside, is captured by the trap surface 31 without being adhered to thesubstrate P. Accordingly, it is possible to avoid the occurrence of anyinconvenience which would be otherwise caused such that the liquid 1remains on the surface of the substrate P. The trap surface 31 isinclined in the upward direction at the outer positions with respect tothe projection area AR1. Therefore, the liquid 1, which intends tooutflow to the outside, can be captured satisfactorily. Further, whenthe scanning direction for the substrate P is reversed to the oppositedirection, then the captured liquid 1 is moved in the downward directionalong the trap surface 31, and hence the liquid 1 is satisfactorilyrecovered by the recovery port 22A which is connected to the trapsurface 31.

The liquid (water) 1, which has the affinity for the liquid contactsurface 2 a disposed at the end of the projection optical system PL thatis higher than the affinity for the photosensitive material coated onthe surface of the substrate P, is supplied from the liquid supplymechanism 10 to perform the liquid immersion exposure. Therefore, theoptical path between the projection optical system PL and the substrateP can be reliably filled with the liquid 1. Further, the liquid (1),which is supplied onto the substrate , is smoothly recovered. Thus, itis possible to avoid the inconvenience including, for example, thescattering and the outflow of the liquid 1.

In this embodiment, when the liquid 1 is supplied from the both sides ofthe projection area AR1 in the scanning direction, the amount of theliquid supplied from the front position in relation to the scanningdirection is larger than the amount of the liquid supplied on the sideopposite thereto. However, the same amounts of the liquid 1 may besupplied from the both sides of the projection area AR1. Also in thiscase, the supply amount of the liquid 1 is not varied even when thescanning direction is switched. Therefore, it is possible to morereliably avoid the occurrence of the water hammer phenomenon. On theother hand, when the amounts of the liquid supplied from the both sidesof the projection area AR1 in the scanning direction are changeddepending on the scanning direction while continuously supplying theliquid 1, it is possible to suppress the amount of use of the liquid 1while suppressing the occurrence of the water hammer phenomenon.

The embodiment of the present invention is constructed such that theliquid 1 is continuously supplied from the supply ports 13A, 14A duringthe operation of the exposure process for one piece of the substrate P.However, the supply may be stopped during the operation. For example,the following procedure may be also available. That is, when thesubstrate P is subjected to the scanning movement toward the +X side,then the liquid supply from the supply port 14A is stopped, and theliquid 1 is supplied from only the supply port 13A. When the substrate Pis subjected to the scanning movement toward the −X side, then theliquid supply from the supply port 13A is stopped, and the liquid 1 issupplied from only the supply port 14A. Further, it is also availablethat the liquid supply mechanism 10 stops the supply of the liquid 1 tothe substrate P during the stepping movement of the substrate P. In thisprocedure, the scanning exposure may be started as follows. That is, theliquid 1 is supplied for a predetermined period of time, and thescanning exposure is performed after waiting for the convergence of thevibration of the liquid. When the procedure or the arrangement asdescribed above is adopted, it is possible to suppress the amount of useof the liquid 1. On the other hand, when the liquid 1 is continuouslysupplied, it is possible to improve the throughput, because it isunnecessary to set any waiting time for the convergence of the vibrationof the liquid.

This embodiment is constructed such that the supply ports 13A, 14A ofthe liquid supply mechanism 10 are provided on the both sides in thescanning direction with respect to the projection area AR1. However, forexample, supply ports (supply members) may be also provided to surroundall of the circumference of the projection area AR1, i.e., also on theboth sides of the projection area AR1 in the non-scanning direction. Theliquid 1 may be supplied onto the substrate P from the respective supplyports provided to surround the projection area AR1. In this arrangement,when the supply ports are provided on the both sides of the projectionarea AR1 in the scanning direction respectively and on the both sides inthe non-scanning direction respectively, i.e., when the mutuallyindependent four supply ports are provided to surround the projectionarea AR1, then the liquid 1 may be supplied from all of the four supplyports, or the liquid 1 may be supplied from only the supply portsprovided on the both sides in the scanning direction while the liquidsupply may be stopped (or a small amount of the liquid may be supplied)from the supply ports provided on the both sides in the non-scanningdirection, when the exposure process is performed while moving thesubstrate P in the scanning direction. The liquid may be supplied fromthe supply ports provided on the both sides in the non-scanningdirection, when the substrate P is moved in the non-scanning direction.Alternatively, the following arrangement is also available. That is, anannular supply member is provided to surround the projection area AR1,and the liquid 1 is supplied onto the substrate P by the aid of thesupply member. In this arrangement, it is enough that one liquid supplyunit is provided to feed the liquid 1 to the supply member. Therefore,it is possible to simplify the arrangement of the apparatus. On theother hand, when the supply ports 13A, 14A are provided on the bothsides in the scanning direction with respect to the projection area AR1as in the embodiment described above, the liquid immersion area AR2 canbe sufficiently formed for the projection area AR1. Thus, it is possibleto suppress the amount of use of the liquid 1.

This embodiment is constructed such that the supply ports 13A, 14A ofthe liquid supply mechanism 10 are provided on the both sides in thescanning direction with respect to the projection area AR1. However,when the space between the projection optical system PL and thesubstrate P is sufficiently filled with the liquid 1, the liquid may besupplied from one supply port arranged near to the projection area AR1.Also in this case, it is possible to suppress the amount of use of theliquid 1 while suppressing the occurrence of the water hammer phenomenonby continuously supplying the liquid from the one supply port until theexposure is completed for all of the shot areas on one substrate P.

In the embodiment described above, the first and second supply members13, 14 and the recovery member 22 are separated from each other.However, the first and second supply members 13, 14 and the recoverymember 22 may be connected to one another. Alternatively, connectingmembers may be provided between the first and second supply members 13,14 and the recovery member 22 to connect them. The embodiment describedabove has been explained such that the internal flow passages 13H, 14Hof the supply members 13, 14 and the internal flow passage 22H of therecovery member 22 are perpendicular to the surface of the substrate P.However, they may be inclined. For example, the internal flow passages13H, 14H (or the supply ports 13A, 14A) of the supply members 13, 14 maybe provided to be directed to the projection area AR1. Further, thedistance (height) of the supply port 13A, 14A from the surface of thesubstrate P may be different from that of the recovery port 22A of therecovery member 22.

It is preferable that the liquid supply mechanism 10 including thesupply members 13, 14 and the liquid recovery mechanism 20 including therecovery member 22 are respectively supported by a support member otherthan the projection optical system PL and a support member forsupporting the projection optical system PL. Accordingly, it is possibleto avoid the transmission, to the projection optical system PL, of thevibration generated in the liquid recovery mechanism 10 and/or theliquid recovery mechanism 20. On the contrary, when the projectionoptical system PL is allowed to make contact with the supply members 13,14 without any gap, it is also possible to expect an effect to preventthe liquid 1 from mixing with the atmospheric air.

Another embodiment of the present invention will be explained below. Inthe following description, the same or equivalent constitutive parts asthose of the embodiment described above are designated by the samereference numerals, any explanation of which will be simplified oromitted.

The liquid recovery mechanism 20 according to the embodiment describedabove is provided with the one liquid recovery unit 21, and the recoverymember 22 which is connected to the liquid recovery unit 21 via therecovery tube 21A and which has the recovery port 22A formedcontinuously to have the annular shape. However, it is also allowablethat a plurality of liquid recovery units are provided. Accordingly, itis possible to suppress the dispersion of the recovery force at each ofthe recovery positions of the recovery port 22A. Further, the controlunit CONT may vary the respective recovery forces of the plurality ofliquid recovery units depending on the liquid recovery positions. Thisarrangement will be explained with reference to FIG. 7.

FIG. 7 shows another embodiment of the present invention, whichschematically depicts a plan view illustrating another example of theliquid recovery mechanism 20. With reference to FIG. 7, the liquidrecovery mechanism 20 includes a first liquid recovery unit 26, a secondliquid recovery unit 27, a first recovery member 28 which is connectedto the first liquid recovery unit 26 via a recovery tube 26A, and asecond recovery member 29 which is connected to the second liquidrecovery unit 27 via a recovery tube 27A. Each of the first and secondrecovery members 28, 29 is formed to be circular arc-shaped as viewed inthe plan view. The first recovery member 28 is arranged on the −X sideof the projection area AR1, while the second recovery member 29 isarranged on the +X side of the projection area AR1. Each of the firstand second recovery members 28, 29 is provided with a recovery portwhich is directed toward the substrate P, and partition members whichare provided therein, in the same manner as in the embodiment describedabove. The recovery operations of the first and second liquid recoveryunits 26, 27 are performed independently by the control unit CONTrespectively.

When the shot area on the substrate P is subjected to the scanningexposure, then the control unit CONT supplies the liquid 1 from theliquid supply mechanism 10 onto the substrate P, and the control unitCONT drives the first and second liquid recovery units 26, 27 of theliquid recovery mechanism 20 respectively to recover the liquid 1 fromthe surface of the substrate P. In this embodiment, the control unitCONT controls the liquid recovery force of the liquid recovery mechanism20 so that the liquid recovery force is varied depending on the liquidrecovery position. Specifically, the control unit CONT makes the settingin relation to the scanning direction such that the recovery amount(recovery force) of the liquid recovered per unit time at the positionin front of the projection area AR1 is smaller than the recovery amountof the liquid recovered on the side opposite thereto. That is, theliquid recovery force is increased on the front side (downstream side ofthe flow of the liquid 1) in the scanning direction. Specifically, whenthe substrate P is moved in the +X direction, the recovery force, whichis exerted by the second recovery member 29 (second liquid recovery unit27) provided on the +X side with respect to the projection area AR1, islarger than the recovery force which is exerted by the first recoverymember 28 (first liquid recovery unit 26) provided on the −X side.Accordingly, it is possible to smoothly perform the operation to recoverthe liquid on the substrate P while avoiding the outflow of the liquid 1to the outside.

The embodiment described above is constructed such that the operationsto recover the liquid by the first and second liquid recovery units 26,27 are performed simultaneously. However, the operations may beperformed separately. For example, the following process is alsoavailable. That is, when the substrate P is moved in the +X direction,then the operation to recover the liquid is performed by using only thesecond recovery member 29 (second liquid recovery unit 27) provided onthe +X side with respect to the projection area AR1, and the operationto recover the liquid, which is to be performed by using the firstrecovery member 28 (first liquid recovery unit 26), is stopped. In thiscase, the liquid 1 principally flows toward the +X side. Therefore, theliquid 1 can be recovered by only the recovery operation performed bythe second liquid recovery unit 27.

In the respective embodiments described above, the recovery member ofthe liquid recovery mechanism 20 is arranged to surround the entireprojection area AR1. However, the recovery members may be provided ononly the both sides of the projection area AR1 in the scanningdirection.

In the respective embodiments described above, the recovery member ofthe liquid recovery mechanism 20 is formed continuously to surround theprojection area AR1. However, as shown in FIG. 8, a plurality ofrecovery members 22D may be arranged discontinuously or intermittently.Similarly, a plurality of supply members 13D, 14D may be arrangeddiscontinuously or intermittently in relation to the liquid supplymechanism 10 as well. Also in this arrangement, the recovery operationis continuously performed with the recovery ports arranged to surroundthe projection area AR1. Therefore, the liquid 1 can be recoveredsatisfactorily even when the liquid 1 is spread while causing thewetting in any direction.

When a plurality of recovery members of the liquid recovery mechanism 20are provided, for example, the liquid recovery force (liquid recoveryamount per unit time) at the position apart from the projection area AR1in the scanning direction may be increased by the liquid recoverymechanism 20 to be larger than the liquid recovery force at anydifferent position, specifically at any position apart in thenon-scanning direction. Accordingly, the liquid 1 on the substrate P canbe smoothly recovered when the scanning exposure is performed.

Alternatively, a plurality of liquid recovery units each having a vacuumpump or the like may be connected through recovery tubes to therespective divided spaces 24 divided by the partition members 23respectively to individually control the recovery operations of theplurality of liquid recovery units so that the recovery force may bevaried depending on the liquid recovery position thereof. Alternatively,the recovery force may be varied depending on the liquid recoveryposition such that the liquid recovery units are not connected to therespective divided spaces 24 individually, one liquid recovery unit isconnected to the plurality of divided spaces 24 through a plurality ofrecovery tubes respectively, and valves are provided for the recoverytubes respectively to adjust the valve opening degrees of the valves.Further, the recovery force can be varied for each of the divided spaces24 by the pressure loss by changing the lengths of the plurality ofrecovery tubes as described above.

In the respective embodiments described above, the supply member of theliquid supply mechanism 10 has the substantially circular arc-shapedform as viewed in the plan view. However, as shown in FIG. 9, the supplymember may have a linear or straight form. In this embodiment, thesupply members 13, 14, which are linear as viewed in the plan view asshown in FIG. 9, are provided on the both sides of the projection areaAR1 in the scanning direction respectively. Similarly, the recoverymember 22 of the liquid recovery mechanism 20 is not limited to have theannular form. As shown in FIG. 9, the recovery member 22 may berectangular.

As shown in FIG. 10A, a porous member 40 may be provided for theinternal flow passage 13H (14H) of the supply member 13 (14) of theliquid supply mechanism 10. Alternatively, as shown in FIG. 10B,partition members 41 may be provided to form slit-shaped flow passages.By doing so, the liquid 1, which is supplied from the supply member 13(14) onto the substrate P, can be rectified. It is possible to suppressthe occurrence of any inconvenience which would be otherwise caused suchthat any turbulence appears on the substrate P and the liquid isvibrated.

The respective embodiments described above have been explained such thatthe trap member 30 (trap surface 31) is elliptical as viewed in the planview. However, the trap member 30 (trap surface 31) may be perfectcircular or rectangular. On the other hand, the liquid 1 tends tooutflow on the both sides of the projection area AR1 in the scanningdirection. Therefore, when the trap member 30 has the elliptical shapeas in the embodiment described above, the liquid 1, which intends tooutflow, can be captured satisfactorily. The embodiment described aboveis constructed such that the trap member 30 (trap surface 31) has theelliptical shape, and the trap member 30 (trap surface 31) is providedat the entire portion outside the liquid recovery positions of therecovery member 22 to surround the recovery member 22. However, it isalso allowable that the trap member 30 (trap surface 31) is provided ononly the both sides of the projection area AR1 in the scanningdirection, and the trap member 30 (trap surface 31) is not provided atany position apart from the projection area AR1 in the non-scanningdirection. The liquid 1, which intends to outflow, can be capturedsatisfactorily by merely providing the trap member 30 on the both sidesof the projection area AR1 in the scanning direction, because the liquid1 tends to outflow on the both sides in the scanning direction. Theangle of inclination of the trap surface 31 may be designed so that theangle of inclination differs depending on the position. For example, theangle of inclination of the trap surface 31 may be increased atpositions in the vicinity of the both sides of the projection area AR1in the scanning direction as compared with those at the other positions.It is not necessarily indispensable that the trap surface 31 is the flatsurface. It is also allowable to use, for example, a shape obtained bycombining a plurality of flat surfaces.

FIG. 11 shows another embodiment of the trap surface 31 of the trapmember 30. As shown in FIG. 11, the trap surface 31 may be a curvedsurface. Specifically, as shown in FIG. 11, the trap surface 31 may be aquadric curve or a circular arc as viewed in a cross section. In thisembodiment, it is preferable that the trap surface 31 is a curvedsurface which is expanded toward the substrate P. Even in the case ofsuch a shape, it is possible to capture the liquid 1 satisfactorily.

Alternatively, as shown in FIG. 12, it is also allowable to apply, tothe trap surface 31, a treatment to enlarge the surface area,specifically, a rough surface-forming treatment. When the roughsurface-forming treatment is applied, then the surface area of the trapsurface 31 is enlarged, and the liquid 1 can be captured moresatisfactorily. It is not necessarily indispensable that the roughsurface-forming treatment is applied to the entire surface of the trapsurface 31. The rough surface-forming treatment may be applied, forexample, to only a part of area disposed in the scanning direction.

As shown in FIG. 13, the trap member 30 may be composed of a pluralityof fin members 32. With reference to FIG. 13, the fin member 32 issubstantially triangular as viewed in a side view. The side (lowerside), which is opposed to the substrate P, is inclined in the upwarddirection at outer positions with respect to the projection area AR1.The plurality of fin members 32 are attached radially to the outer sidesurface of the recovery member 22 so that the longitudinal directionthereof is directed outwardly. In this embodiment, the plurality of finmembers 32 are separated from each other. Space sections 33 are formedbetween the respective fin members 32. The liquid 1, which isunsuccessfully recovered by the recovery member 22, is captured by thesurface tension by the space sections 33 between the fin members 32.Accordingly, the liquid 1 is prevented from the outflow to the outsideof the substrate P.

The plurality of fin members 32 may be provided at equal intervals, orthey may be provided at unequal intervals. For example, the intervalsbetween the fin members 32 provided at positions in the scanningdirection may be set to be smaller than the intervals between the finmembers 32 provided at positions in the non-scanning direction. Theplurality of fin members 32 may have an identical length (size in theradial direction) respectively. Alternatively, the fin member 32, whichis provided at the position in the scanning direction, may have a lengththat is longer than the length of the fin member 32 which is provided atthe position other than the above. A part of the area for the trapmember 30 may be composed of the fin members, and the remaining area maybe composed of the trap surface. The fin members 32 may be attached tothe trap surface 31 as explained, for example, with reference to FIG. 4.It is preferable that the liquid-attracting treatment is also applied tothe surface of the fin member 32 in order to enhance the affinity forthe liquid 1.

In the respective embodiments described above, when theliquid-attracting treatment is applied to the trap surface 31 (or thefin members 32), the liquid-attracting property of the trap surface 31may be allowed to posses a distribution. In other words, the surfacetreatment can be performed so that the contact angles of the liquid aremutually different values for a plurality of areas on the surface to besubjected to the surface treatment. For example, the liquid-attractingproperty may be lowered in a part of the area of the trap surface 31disposed outside the projection area AR1 as compared with the areadisposed inside. Further, it is not necessarily indispensable that allof the trap surface 31 is subjected to the liquid-attracting treatment.For example, only a part of the area disposed in the scanning directionmay be subjected to the liquid-attracting treatment.

The embodiment described above has been explained such that theliquid-attracting treatment is applied to the trap surface 31. However,the liquid-attracting treatment can be also applied to the surface ofthe flow passage through which the liquid 1 flows, included in theliquid supply mechanism 10 and/or the liquid recovery mechanism 20. Inparticular, when the liquid-attracting treatment is applied to therecovery member 22 of the liquid recovery mechanism 20, the liquid canbe recovered smoothly. Alternatively, the liquid-attracting treatmentcan be also applied to the end portion of the projection optical systemPL including the barrel PK with which the liquid 1 makes contact. When athin film is formed on the optical element 2, then the thin film isformed of a material having a transmittance with respect to the exposurelight beam EL, and the film thickness thereof is designed to such anextent that the exposure light beam EL can be transmitted therethrough,because the thin film is arranged on the optical path for the exposurelight beam EL.

The thin film for the surface treatment may be either a single layerfilm or a film composed of a plurality of layers. As for the materialfor forming the thin film, it is possible to use arbitrary materialsprovided that the material can exhibit the desired performance,including, for example, metals, metal compounds, and organic matters.

The surface treatment may be also applied to the surface of thesubstrate P in conformity with the affinity for the liquid 1. Asdescribed above, it is preferable that the affinity of the trap surface31 for the liquid is higher than the affinity of the surface of thesubstrate P for the liquid.

Next, an explanation will be made with reference to FIG. 14 about stillanother embodiment of a liquid supply mechanism 10 and a liquid recoverymechanism 20 according to the present invention.

With reference to FIG. 14, the liquid supply mechanism 10 includes afirst liquid supply unit 11, a second liquid supply unit 12, a firstsupply member 13 which is provided on one side (−X side) in the scanningdirection with respect to the projection area AR1, a second supplymember 14 which is provided on the other side (+X side), a first supplytube 41 which connects the first liquid supply unit 11 and the firstsupply member 13 with each other, and a second supply tube 42 whichconnects the second liquid supply unit 12 and the second supply member14 with each other. The first and second supply members 13, 14 includeinternal flow passages 13H, 14H and supply ports 13A, 14A formed attheir lower ends respectively, which are formed to be substantiallycircular arc-shaped as viewed in a plan view, in the same manner as inthe embodiment described with reference to FIGS. 2 and 3.

The first supply tube 41, which connects the first liquid supply unit 11and the first supply member 13, has a straight tube section 43 and aslit tube section 44. One end of the straight tube section 43 isconnected to the first liquid supply unit 11, and the other end of thestraight tube section 43 is connected to one end of the slit tubesection 44. The other end of the slit tube section 44 is connected tothe upper end of the internal flow passage 13H of the first supplymember 13. One end of the slit tube section 44 is formed to haveapproximately the same size as that of the straight tube section 43, andthe other end thereof is formed to have approximately the same size asthat of the upper end of the first supply member 13. The slit tubesection 44 is formed to be substantially triangular as viewed in a planview so that the slit tube section 44 is gradually widened in thehorizontal direction from one end to the other end. A slit-shapedinternal flow passage 44H, which is formed in the slit tube section 44,is formed so that the internal flow passage 44H is gradually widened inthe horizontal direction from one end to the other end.

Similarly, the second supply tube 42, which connects the second liquidsupply unit 12 and the second supply member 14, has a straight tubesection 45 and a slit tube section 46. One end of the straight tubesection 45 is connected to the second liquid supply unit 12, and theother end of the straight tube section 45 is connected to one end of theslit tube section 46. The other end of the slit tube section 46 isconnected to the upper end of the internal flow passage 14H of thesecond supply member 14. One end of the slit tube section 46 is formedto have approximately the same size as that of the straight tube section45, and the other end thereof is formed to have approximately the samesize as that of the upper end of the second supply member 14. The slittube section 46 is formed to be substantially triangular as viewed in aplan view so that the slit tube section 46 is gradually widened in thehorizontal direction from one end to the other end. A slit-shapedinternal flow passage 46H, which is formed in the slit tube section 46,is formed so that the internal flow passage 46H is gradually widened inthe horizontal direction from one end to the other end.

The liquid recovery mechanism 20 includes a recovery member 22 which isformed to be annular as viewed in a plan view, a plurality of liquidrecovery units 61 to 64, and a plurality of recovery tubes 71 to 74which connect the recovery member 22 and the respective liquid recoveryunits 61 to 64 to one another. In this embodiment, the liquid recoveryunits include four of the first to fourth liquid recovery units 61 to64, and the recovery tubes include four of the first to fourth recoverytubes 71 to 74 corresponding thereto. The recovery member 22 includes anannular internal flow passage 22H, and a recovery port 22A formed at thelower end thereof, in the same manner as in the embodiment explainedwith reference to FIGS. 2 and 3. No partition member (23) is providedfor the internal flow passage 22H of the embodiment shown in FIG. 14.The recovery members 22 of the liquid recovery mechanism 20 are arrangedoutside the first and second supply members 13, 14 of the liquid supplymechanism 10.

The first recovery tube 71, which connects the first liquid recoveryunit 61 included in the plurality of liquid recovery units and therecovery member 22, has a straight tube section 75 and a slit tubesection 76. One end of the straight tube section 75 is connected to thefirst liquid recovery unit 61, and the other end of the straight tubesection 75 is connected to one end of the slit tube section 76. Theother end of the slit tube section 76 is connected to the upper end ofthe internal flow passage 22H of the recovery member 22. In thisembodiment, one end of the slit tube section 76 is formed to haveapproximately the same size as that of the straight tube section 75,while the other end of the slit tube section 76 is formed to have a sizewhich is approximately ¼ of the upper end of the annular recovery member22. The slit tube section 76 is formed to be substantially triangular asviewed in a plan view so that the slit tube section 76 is graduallywidened in the horizontal direction from one end to the other end. Aslit-shaped internal flow passage 76H, which is formed in the slit tubesection 76, is formed so that the internal flow passage 76H is graduallywidened in the horizontal direction from one end to the other end.

Similarly, the second recovery tube 72, which connects the second liquidrecovery unit 62 and the recovery member 22, has a straight tube section77 and a slit tube section 78. One end of the slit tube section 78 isformed to have approximately the same size as that of the straight tubesection 77, while the other end of the slit tube section 78 is formed tohave a size which is approximately ¼ of the upper end of the annularrecovery member 22. The slit tube section 78 is formed to besubstantially triangular as viewed in a plan view. A slit-shapedinternal flow passage 78H, which is formed in the slit tube section 78,is formed so that the internal flow passage 78H is gradually widened inthe horizontal direction from one end to the other end. Further, thethird recovery tube 73, which connects the third liquid recovery unit 63and the recovery member 22, has a straight tube section 79 and a slittube section 80. The fourth recovery tube 74, which connects the fourthliquid recovery unit 64 and the recovery member 22, has a straight tubesection 81 and a slit tube section 82. Each of the other ends of theslit tube sections 80, 82 is formed to have a size which isapproximately ¼ of the upper end of the annular recovery member 22. Eachof the slit tube sections 80, 82 is formed to be substantiallytriangular as viewed in a plan view. Slit-shaped internal flow passages80H, 82H, which are formed in the slit tube sections 80, 82respectively, are formed so that each of the internal flow passages 80H,82H is gradually widened in the horizontal direction from one end to theother end.

The members for allowing the liquid to flow therethrough, specificallythe supply tubes 41, 42 and the recovery tubes 71 to 74, which areincluded in the members for constructing the liquid supply mechanism 10and the liquid recovery mechanism 20, may be made of synthetic resinsuch as polytetrafluoroethylene as described above. Alternatively, forexample, they may be made of metal such as stainless steel and aluminum.In this embodiment, the members, through which the fluid flows, are madeof metal. In particular, when the members for constructing the flowpassages for the liquid, which are included in the liquid supplymechanism 10 and the liquid recovery mechanism 20, are made of aluminum,it is possible to allow the liquid to flow smoothly, because aluminumhas the small contact angle with respect to the liquid (water). Althoughnot shown in FIG. 14, the trap member 30 is provided around the recoverymember of the liquid recovery mechanism 20 in the same manner as in theembodiment described above.

Next, an explanation will be made about the operation of the liquidsupply mechanism 10 and the liquid recovery mechanism 20. In order toform the liquid immersion area (AR2), the control unit CONT drives thefirst and second liquid supply units 11, 12 of the liquid supplymechanism 10 respectively. The liquid 1, which is fed from the first andsecond liquid supply units 11, 12 respectively, flows through the firstand second supply tubes 41, 42 respectively, and the liquid 1 issupplied onto the substrate P via the first and second supply members13, 14. In this embodiment, the liquid 1, which is fed from the firstliquid supply unit 11, flows through the straight tube section 43 of thefirst supply tube 41, and then the liquid 1 flows through the slit tubesection 44. Accordingly, the liquid 1 is spread in the horizontaldirection (lateral direction). The liquid 1 is spread at the other endof the slit tube section 44 to a size approximately equal to the size ofthe internal flow passage 13H (supply port 13A) of the first supplymember 13 in the Y axis direction. After that, the liquid 1 is suppliedonto the substrate P via the internal flow passage 13H of the firstsupply member 13. Accordingly, the liquid 1 is supplied onto thesubstrate P at approximately uniform liquid supply amounts at therespective positions of the substantially circular arc-shaped supplyport 13A in which the longitudinal direction extends in the Y axisdirection. Similarly, the liquid 1, which is fed from the second liquidsupply unit 12, also flows through the straight tube section 45 of thesecond supply tube 42, and then the liquid 1 is spread in the horizontaldirection (lateral direction) via the slit tube section 46. After that,the liquid 1 is supplied to the second supply member 14. Therefore, theliquid 1 is supplied onto the substrate P at approximately uniformliquid supply amounts at the respective positions of the supply port14A.

That is, in the embodiment described with reference to FIGS. 2 and 3,the entire supply tube 11A is constructed by the straight tube.Therefore, when the liquid is directly supplied from the supply tube 11Aas the straight tube to the first supply member 13 in which thelongitudinal direction extends in the Y axis direction, the differencein the flow passage area causes the difference between the liquid supplyamount at the central portion in the longitudinal direction of thesupply port 13A of the first supply member 13, i.e., at the positiondisposed just under the supply tube 11A and the liquid supply amount atthe end of the supply port 13A in the longitudinal direction, i.e., atthe position separated from the supply tube 11A. As a result, the liquidsupply amount is sometimes nonuniform at the respective positions of thesupply port 13A. Specifically, the liquid supply amount at the centralportion of the supply port 13A in the longitudinal direction (positiondisposed just under the supply tube 11A) is larger than the liquidsupply amount at the end of the supply port 13A in the longitudinaldirection (position separated from the supply tube 11A). It isimpossible to supply the liquid uniformly, and there is such apossibility that the liquid immersion area AR2 may be nonuniform.However, when the liquid 1 is supplied from the first liquid supply unit11 to the first liquid supply member 13 (supply port 13A) in which thelongitudinal direction extends in the Y axis direction, the size of theflow passage of at least a part of the supply tube 41 is set dependingon the size of the first supply member 13. As in this embodiment, a partof the supply tube 41 is provided as the slit tube section 44 having thetapered internal flow passage 44H which is gradually widened in thehorizontal direction toward the first supply member 13. Accordingly, theliquid 1 can be supplied onto the substrate P at the approximatelyuniform liquid supply amounts at the respective positions of the supplyport 13A of the first supply member 13 in which the longitudinaldirection extends in the Y axis direction. Similarly, the liquid 1,which is fed from the second liquid supply unit 12, is also suppliedonto the substrate P uniformly through the second supply tube 42 and thesecond supply member 14.

The control unit CONT drives the first to fourth liquid recovery units61 to 64 of the liquid recovery mechanism 20 respectively to recover theliquid 1 from the surface of the substrate P by the aid of the recoverymember 22 and the first to fourth recovery tubes 71 to 74 respectively.The first to fourth liquid recovery units 61 to 64 recover the liquid 1by sucking the liquid 1 from the surface of the substrate P through thefirst to fourth recovery tubes 71 to 74 respectively. The liquid 1 isrecovered from the substrate P at approximately uniform recovery amounts(recovery forces) at the respective positions of the recovery port 22Aof the annular recovery member 22.

That is, when the recovery-tube as the straight tube is directlyconnected to the recovery member 22 in the same manner as describedabove, then the difference in the flow passage area causes thedifference in the liquid recovery amount (recovery force) at each of thepositions of the recovery port 22A, and the liquid recovery amount maybe nonuniform at each of the positions of the recovery port 22A in somecases. For example, the liquid recovery amount at the position disposedjust under the recovery tube is larger than the liquid recovery amountat the positions other than the above. There is such a possibility thatthe liquid cannot be recovered uniformly and the liquid immersion areaAR2 may be nonuniform. However, when parts of the recovery tubes are theslit tube sections 76, 78, 80, 82 each of which has the tapered internalflow passage that is gradually widened in the horizontal directiontoward the recovery member 22 as in this embodiment, the liquid can berecovered from the substrate P at the approximately uniform liquidrecovery amounts at the respective positions of the recovery port 22A ofthe annular recovery member 22.

As described above, the liquid can be supplied uniformly at therespective positions of the supply ports 13A, 14A respectively, and theliquid can be recovered uniformly at the respective positions of therecovery port 22A. Therefore, it is possible to form the uniform liquidimmersion area AR2.

In the embodiment described with reference to FIG. 14, the internal flowpassage 44H (46H) of the slit tube section 44 (46) is hollow. However,as shown in FIG. 15, a plurality of fin members 85 may be provided inthe flow direction of the liquid 1 (from one end to the other end of theslit tube section) for the internal flow passage 44H (46H) of the slittube section 44 (46) which constitutes a part of the supply tube 41 (42)of the liquid supply mechanism 10. Accordingly, the liquid 1 can besupplied onto the substrate P by the aid of the supply member 13 (14)after rectifying the liquid 1. The fin members 85 may be elongated toextend over the internal flow passage 13H (14H) of the supply member 13(14). Such fin members 85 may be provided for the internal flow passages76H, 78H, 80H, 82H of the slit tube sections 76, 78, 80, 82 whichconstruct the recovery tubes of the liquid recovery mechanism 20respectively.

For example, when the substrate P is subjected to the scanning movementat a high velocity, the following situation may be conceived. That is,the liquid 1 cannot be recovered sufficiently from the substrate P evenin the case of the embodiment shown in FIG. 14, and the liquid 1 on thesubstrate P may outflow to the outside of the recovery member 22. Insuch a situation, the lower surfaces of the slit tube sections 44, 46each having the substantially triangular shape as viewed in a plan viewprovided at the positions in the scanning direction (X axis direction)of the substrate P can be used as trap surfaces in place of the trapmember 30.

This embodiment is constructed such that the plurality of recovery tubes71 to 74 are connected to one recovery member 22. However, a pluralityof recovery members (recovery ports) may be provided closely to thesubstrate P so that the plurality of recovery members (recovery ports)correspond to the plurality of recovery tubes 71 to 74.

Next, an explanation will be made about still another embodiment of aliquid supply mechanism 10 and a liquid recovery mechanism 20 accordingto the present invention with reference to FIGS. 16 to 19.

FIG. 16 shows a schematic perspective view illustrating the liquidsupply mechanism (10) and the liquid recovery mechanism (20) accordingto this embodiment. With reference to FIG. 16, the liquid supplymechanism (10) includes first and second liquid supply units 11, 12, andfirst and second supply tubes 41, 42 which are connected to the firstand second liquid supply units 11, 12 respectively. The liquid recoverymechanism (20) includes first to fourth liquid recovery units 61 to 64,and first to fourth recovery tubes 71 to 74 which are connected to thefirst to fourth liquid recovery units 61 to 64 respectively. One end ofeach of the first and second recovery tubes 41, 42 is connected to eachof the first and second liquid supply units 11, 12. The other end isconnected to each of supply passages formed by a flow passage-formingmember 90 as described later on. One end of each of the first to fourthrecovery tubes 71 to 74 is connected to each of the first to fourthliquid recovery units 61 to 64. The other end is connected to each ofrecovery passages formed by the flow passage-forming member 90 asdescribed later on.

The flow passage-forming member 90 includes a first member 90, a secondmember 92 which is arranged on the first member 91, and a third member93 which is arranged on the second member 92. The flow passage-formingmember 90 is arranged to surround the projection optical system PL. Thefirst to third members 91 to 93, which constitute the flowpassage-forming member 90, are rectangular plate members having anidentical outer size respectively, and they have holes 91A to 93Adisposed at central portions thereof so that the projection opticalsystem PL may be arranged therein. The holes 91A to 93A are formed sothat they are communicated with each other. The first and second supplytubes 41, 42 are connected to the third member 93 disposed at theuppermost stage of the first to third members. The first to fourthrecovery tubes 71 to 74 are connected to the second member 92 disposedat the middle stage.

FIG. 17 shows a perspective view illustrating the first member 91 whichis arranged at the lowermost stage of the first to third members. Thefirst member 91 includes a first supply hole 94A which is formed on the−X side of the projection optical system PL and which forms a supplyport for supplying the liquid 1 to the substrate P, and a second supplyhole 95A which is formed on the +X side of the projection optical systemPL and which forms a supply port for supplying the liquid to thesubstrate P. Each of the first supply hole 94A and the second supplyhole 95A is formed to be substantially circular arc-shaped as viewed ina plan view. The first member 91 further includes a first recovery hole96A which is formed on the −X side of the projection optical system PLand which forms a recovery port for recovering the liquid on thesubstrate P, a second recovery hole 97A which is formed on the −Y sideof the projection optical system PL and which forms a recovery port forrecovering the liquid on the substrate P, a third recovery hole 98Awhich is formed on the +X side of the projection optical system PL andwhich forms a recovery port for recovering the liquid on the substrateP, and a fourth recovery hole 99A which is formed on the +Y side of theprojection optical system PL and which forms a recovery port forrecovering the liquid on the substrate P. Each of the first to fourthrecovery holes 96A to 99A is formed to be substantially circulararc-shaped as viewed in a plan view. The first to fourth recovery holes96A to 99A are provided at substantially equal intervals along thecircumference of the projection optical system PL. The recovery holes96A to 99A are provided on the outer side with respect to the projectionoptical system PL as compared with the supply holes 94A, 95Brespectively.

FIG. 18 shows perspective views illustrating the second member 92arranged at the middle stage of the first to third members. FIG. 18Ashows a perspective view as viewed from an upper position, and FIG. 18Bshows a perspective view as viewed upwardly from a lower position. Thesecond member 92 includes a third supply hole 94B which is formed on the−X side of the projection optical system PL and which is to be connectedto the first supply hole 94A of the first member 91, and a fourth supplyhole 95B which is formed on the +X side of the projection optical systemPL and which is to be connected to the second supply hole 95A of thefirst member 91. The respective shapes and the sizes of the third andfourth supply holes 94B, 95B correspond to those of the first and secondsupply holes 94A, 95A.

The second member 92 further includes, on the lower surface, a firstrecovery groove 96B which is formed on the −X side of the projectionoptical system PL and which is to be connected to the first recoveryhole 96A of the first member 91, a second recovery groove 97B which isformed on the −Y side of the projection optical system PL and which isto be connected to the second recovery hole 97A of the first member 91,a third recovery groove 98B which is formed on the +X side of theprojection optical system PL and which is to be connected to the thirdrecovery hole 98A of the first member 91, and a fourth recovery groove99B which is formed on the +Y side of the projection optical system PLand which is to be connected to the fourth recovery hole 99A of thefirst member 91. The first to fourth recovery grooves 96B to 99B areformed to be substantially circular arc-shaped as viewed in a plan viewrespectively so as to correspond to the shapes and the sizes of thefirst to fourth recovery holes 96A to 99A. The first to fourth recoverygrooves 96B to 99B are provided at substantially equal intervals alongthe circumference of the projection optical system PL. The firstrecovery tube 71 is connected to the first recovery groove 96B via atapered groove 96T. The tapered groove 96T is formed so that the taperedgroove 96T is gradually widened in the horizontal direction from theconnecting portion with respect to the first recovery tube 71 toward thefirst recovery groove 96B. Similarly, the second recovery tube 72 isconnected to the second recovery groove 97B via a tapered groove 97T,the third recovery tube 73 is connected to the third recovery groove 98Bvia a tapered groove 98T, and the fourth recovery tube 74 is connectedto the fourth recovery groove 99B via a tapered groove 99T.

FIG. 19 shows perspective views illustrating the third member 93arranged at the uppermost stage of the first to third members. FIG. 19Ashows a perspective view as viewed from an upper position, and FIG. 19Bshows a perspective view as viewed upwardly from a lower position. Thethird member 93 includes, on the lower surface, a first supply groove94C which is formed on the −X side of the projection optical system PLand which is to be connected to the third supply hole 94B of the secondmember 92, and a second supply groove 95C which is formed on the +X sideof the projection optical system PL and which is to be connected to thefourth supply hole 95B of the second member 92. The shapes and the sizesof the first and second supply grooves 94C, 95 are formed to besubstantially circular arc-shaped as viewed in a plan view respectivelyso as to correspond to those of the third and fourth supply holes 94B,95B (as well as those of the first and second supply holes 94A, 95A).The first supply tube 41 is connected to the first supply groove 94C viaa tapered groove 94T. The tapered groove 94T is formed so that thetapered groove 94T is gradually widened in the horizontal direction fromthe connecting portion with respect to the first supply tube 41 towardthe first supply groove 94C. Similarly, the second supply tube 42 isconnected to the second supply groove 95C via a tapered groove 95T.

The first to third members 91 to 93 are formed of metal including, forexample, stainless steel, titanium, aluminum, and alloy containing theabove. The holes and the grooves of the respective members 91 to 93 areformed, for example, by the electric discharge machining. The flowpassage-forming member 90 is formed by joining the respective members 91to 93 by using, for example, an adhesive or a thermocompression bondingmethod after processing the respective members 91 to 93 by the electricdischarge machining. The tapered groove 94T, the first supply groove94C, the third supply hole 94B, and the first supply hole 94A areconnected to one another (communicated with each other) by stacking andjoining the respective members 91 to 93. Thus, the supply flow passage,which is connected to (communicated with) the first supply tube 41, isformed. Similarly, the tapered groove 95T, the second supply groove 95C,the fourth supply hole 95B, and the second supply hole 95A are connectedto one another (communicated with each other), and thus the supply flowpassage, which is connected to (communicated with) the second supplytube 42, is formed. The liquid 1, which is fed from the first and secondliquid supply units 11, 12 respectively, is supplied onto the substrateP through the first and second supply tubes 41, 42 and the supplypassages described above. That is, the liquid supply flow passages areformed by stacking the plate members 91 to 93.

The recovery flow passage, which is connected to (communicated with) thefirst recovery tube 71, is formed by connecting (communicating) thetapered groove 96T, the first recovery groove 96B, and the firstrecovery hole 96A respectively. Similarly, the recovery flow passage,which is connected to (communicated with) the second recovery tube 72,is formed by connecting (communicating) the tapered groove 97T, thesecond recovery groove 97B, and the second recovery hole 97Arespectively. The recovery flow passage, which is connected to(communicated with) the third recovery tube 73, is formed by connecting(communicating) the tapered groove 98T, the third recovery groove 98B,and the third recovery hole 98A respectively. The recovery flow passage,which is connected to (communicated with) the fourth recovery tube 74,is formed by connecting (communicating) the tapered groove 99T, thefourth recovery groove 99B, and the fourth recovery hole 99Arespectively. That is, the liquid recovery flow passages are formed bystacking the plate members 91 to 93. The liquid on the substrate P isrecovered through the recovery flow passages and the first to thirdrecovery tubes 71 to 74 respectively.

In this arrangement, the tapered grooves 94T, 95T are connected to thefirst and second supply tubes 41, 42 respectively. Therefore, the liquidcan be supplied uniformly at respective positions of the supply ports inwhich the longitudinal direction extends in the Y axis direction, in thesame manner as in the embodiment described with reference to FIG. 14.Similarly, the tapered grooves are connected to the recovery tubes 71 to74 respectively. Therefore, the liquid can be recovered with the uniformrecovery force.

Owing to the construction that the flow passage-forming member 90 isformed by the first to third members 91 to 93 as the plate membersrespectively, for example, the flow passage-forming member 90 can beused to absorb the vibration generated when the liquid is sucked whilebeing mixed with the air upon the recovery of the liquid. Further, themachining such as the electric discharge machining is applied to each ofthe plurality of plate members 91 to 93 to form parts of the flowpassages, and the flow passages for the liquid are formed by combiningthem. Therefore, the supply flow passages and the recovery flow passagescan be formed with ease respectively.

Surfaces, which are inclined with respect to the XY plane, may beprovided around the first to fourth recovery holes 96A to 99A disposedon the lower surface of the first member 91 arranged at the lowermoststage of the plurality of members 91 to 93 for forming the flowpassage-forming member 90, and the surfaces may be subjected to theliquid-attracting treatment. Accordingly, the surfaces may be used astrap surfaces to capture the liquid unsuccessfully recovered by theliquid recovery mechanism. The members 91 to 93 for forming the flowpassage-forming member 90 are the rectangular or square plate members.However, it is also allowable to use circular plate members, and it isalso allowable to use elliptical plate members which are long in the Xdirection.

Both of the supply flow passages and the recovery flow passages areformed in the flow passage-forming member 90 described above. However,only any one of the flow passages may be provided in the flowpassage-forming member 90. Alternatively, flow passage-forming members,each of which is formed by stacking a plurality of members, may bedivided into a flow passage-forming member for the supply flow passagesand a flow passage-forming member for the recovery flow passages, andthey may be provided separately.

Next, still another embodiment of the present invention will beexplained. As described above, it is preferable to support each of theliquid supply mechanism 10 including the supply members 13, 14 and theliquid recovery mechanism 20 including the recovery member 22 by using asupport member other than the projection optical system PL and anysupport member for supporting the projection optical system PL. Anexplanation will be made below about a support structure for supportingeach of the liquid supply mechanism 10 and the liquid recovery mechanism20 with reference to FIG. 20.

FIG. 20 schematically shows the support structure for the liquid supplymechanism 10 and the liquid recovery mechanism 20. With reference toFIG. 20, the exposure apparatus EX includes a barrel base plate (firstsupport member) 100 which supports the projection optical system PL, anda main frame (second support member) 102 which supports the barrel baseplate 100, the mask stage MST, and the substrate stage PST. In FIG. 20,the Z stage and the XY stage are shown as an integrated unit. The mainframe 102 is installed substantially horizontally by the aid of legs 108on the floor surface in a clean room or the like. The main frame 102 isformed with an upper stage 102A and a lower stage 102B which protrudeinwardly.

The illumination optical system IL is supported by a support frame 120which is fixed to the upper portion of the main frame 102. A mask baseplate 124 is supported on the upper stage 102A of the main frame 102 bythe aid of an anti-vibration apparatus 122. Openings are formed throughcentral portions of the mask stage MST and the mask base plate 124 forallowing the pattern image of the mask M to pass therethrough. Aplurality of air bearings 126, which are non-contact bearings, areprovided on the lower surface of the mask stage MST. The mask stage MSTis supported in a non-contact manner by the air bearings 126 withrespect to the upper surface (guide surface) of the mask base plate 124.The mask stage MST is movable two-dimensionally in the XY plane andfinely rotatable in the θZ direction by the aid of the maskstage-driving unit.

A flange 104 is provided on the outer circumference of the barrel PK forholding the projection optical system PL. The projection optical systemPL is supported by the barrel base plate 100 by the aid of the flange104. An anti-vibration apparatus 106 including an air mount or the likeis arranged between the barrel base plate 100 and the lower stage 102Bof the main frame 102. The barrel base plate 100, which supports theprojection optical system PL, is supported by the lower stage 102B ofthe main frame 102 by the aid of the anti-vibration apparatus 106. Thebarrel base plate 100 is isolated from the main frame 102 in terms ofthe vibration (in relation to the vibration) by the anti-vibrationapparatus 106 so that the vibration of the main frame 102 is nottransmitted to the barrel base plate 100 which supports the projectionoptical system PL.

A plurality of air bearings 130, which are non-contact bearings, areprovided on the lower surface of the substrate stage PST. A stage base112 is supported on the main frame 102 by the aid of an anti-vibrationapparatus 110 including an air mount or the like. The substrate stagePST is supported in a non-contact manner by the air bearing 130 withrespect to the upper surface (guide surface) of the stage base 112. Thesubstrate stage PST is movable two-dimensionally in the XY plane andfinely rotatable in the θZ direction by the aid of the substratestage-driving unit. Further, the substrate stage PST is also movable inthe Z axis direction, the θx direction, and the θY direction. The stagebase 112 is isolated from the main frame 102 in terms of the vibrationby the anti-vibration apparatus 110 so that the vibration of the mainframe 102 is not transmitted to the stage base 112 which supports thesubstrate stage PST in the non-contact manner.

A movement mirror 55 is provided at a predetermined position on the +Xside on the substrate stage PST, and a reference mirror (fixed mirror)114 is provided at a predetermined position on the +X side on the barrelPK. A laser interferometer 56 is provided at a position opposed to themovement mirror 55 and the reference mirror 114. The laserinterferometer 56 is attached to the barrel base plate 100. Therefore,the laser interferometer 56 is isolated from the liquid supply mechanism10 and the liquid recovery mechanism 20 in terms of the vibration. Thelaser interferometer 56 radiates the length-measuring beam (measuringlight beam) onto the movement mirror 55, and it radiates the referencebeam (reference light beam) onto the reference mirror 114. Reflectedlight beams, which come from the movement mirror 55 and the referencemirror 114 respectively on the basis of the radiated length-measuringbeam and the reference beam, are received by a light-receiving unit ofthe laser interferometer 56. The laser interferometer 56 causes theinterference with the light beams to measure the amount of change of theoptical path length of the length-measuring beam on the basis of theoptical path length of the reference beam, and consequently the positioninformation about the movement mirror 55 on the basis of the referencemirror 114, i.e., the position information about the substrate stagePST. Similarly, although not shown, a movement mirror and a referencemirror are also provided on the +Y side on the substrate stage PST andthe barrel PK, and a laser interferometer is provided at a positionopposed thereto.

Those supported by the barrel base plate 100 also include unillustratedmeasuring systems such as the auto-focus detecting system for measuringthe focus position (Z position) and the inclination of the substrate Pand the alignment system for detecting the alignment mark on thesubstrate P. The measuring systems as described above are also isolatedfrom the main frame 102, the liquid supply mechanism 10, and the liquidrecovery mechanism 20 in terms of the vibration.

The liquid supply mechanism 10 and the liquid recovery mechanism 20 aresupported by the lower stage 102B of the main frame 102. This embodimentis constructed such that the first and second supply members 13, 14 andthe supply tubes 11A, 12A for constructing the liquid supply mechanism10, the recovery member 22 and the recovery tube 21A for constructingthe liquid recovery mechanism 20 and other components are supported bythe support member 140, and the support member 140 is connected to thelower stage 102B of the main frame 102. FIG. 20 is illustrated whilesimplifying, for example, the supply members 13, 14, the recovery member22, the supply tubes 11A, 12A, and the recovery tube 21A.

As described above, the liquid supply mechanism 10 and the liquidrecovery mechanism 20 are supported by the main frame 102 which isisolated in terms of the vibration from the barrel base plate 100 whichsupports the projection optical system PL. Accordingly, the liquidsupply mechanism 10 and the liquid recovery mechanism 20 are isolatedfrom the projection optical system PL in terms of the vibration.Therefore, the vibration, which is generated when the liquid is suppliedand/or when the liquid is recovered, is not transmitted via the barrelbase plate 100 to the projection optical system PL, the laserinterferometer 56, and the measuring systems such as the autofocusdetecting system and the alignment system. Therefore, it is possible toavoid the occurrence of any inconvenience which would be otherwisecaused such that the pattern image is deteriorated by the vibration ofthe projection optical system. Further, it is possible to accuratelyperform the position control of the substrate stage (substrate P).Therefore, it is possible to accurately project the pattern image ontothe substrate. The liquid supply mechanism 10 and the liquid recoverymechanism 20 are supported by the main frame 102 which is isolated interms of the vibration from the stage base 112 which supports thesubstrate stage PST. Accordingly, the liquid supply mechanism 10 and theliquid recovery mechanism 20 are isolated from the stage base 112 interms of the vibration. Therefore, the vibration, which is generatedwhen the liquid is supplied and/or when the liquid is recovered, is nottransmitted to the stage base 112 as well. It is possible to avoid theoccurrence of any inconvenience which would be otherwise caused suchthat the positioning accuracy and/or the movement accuracy of thesubstrate stage PST is lowered.

In this embodiment, the liquid supply mechanism 10 and the liquidrecovery mechanism 20 are integrally supported by the main frame 102.However, the liquid supply mechanism 10 and the liquid recoverymechanism 20 may be separately attached to the main frame 102. Further,a support member, which is distinct from the main frame 102, may bearranged on the floor in the clean room or the like, and the liquidsupply mechanism and the liquid recovery mechanism may be supported bythe support member.

As described above, pure water is used as the liquid 1 in theembodiments of the present invention. Pure water is advantageous in thatpure water is available in a large amount with ease, for example, in thesemiconductor production factory, and pure water exerts no harmfulinfluence, for example, on the optical element (lens) and thephotoresist on the substrate P. Further, pure water exerts no harmfulinfluence on the environment, and the content of impurity is extremelylow. Therefore, it is also expected to obtain the function to wash thesurface of the substrate P and the surface of the optical elementprovided at the end surface of the projection optical system PL. It isapproved that the refractive index n of pure water (water) with respectto the exposure light beam EL having a wavelength of about 193 nm isapproximately in an extent of 1.44. When the ArF excimer laser beam(wavelength: 193 nm) is used as the light source of the exposure lightbeam EL, then the wavelength is shortened on the substrate P by 1/n,i.e., to about 134 nm, and a high resolution is obtained. Further, thedepth of focus is magnified about n times, i.e., about 1.44 times ascompared with the value obtained in the air. Therefore, when it isenough to secure an approximately equivalent depth of focus as comparedwith the case of the use in the air, it is possible to further increasethe numerical aperture of the projection optical system PL. Also in thisviewpoint, the resolution is improved.

When the liquid immersion method as described above is used, thenumerical aperture NA of the projection optical system is 0.9 to 1.3 insome cases. When the numerical aperture NA of the projection opticalsystem is increased as described above, the image formation performanceis sometimes deteriorated by the polarization effect with the randompolarized light beam having been hitherto used as the exposure lightbeam. Therefore, it is desirable to use the polarized illumination. Inthis case, the following procedure is preferred. That is, the linearpolarized illumination is effected, which is adjusted to thelongitudinal direction of the line pattern of the line-and-space patternof the mask (reticle) so that a large amount of diffracted light of theS-polarized component (component in the polarization direction along thelongitudinal direction of the line pattern) is allowed to outgo from thepattern of the mask (reticle). When the space between the projectionoptical system PL and the resist coated on the surface of the substrateP is filled with the liquid, the diffracted light of the S-polarizedcomponent, which contributes to the improvement in the contrast, has thetransmittance through the resist surface that is raised to be high ascompared with a case in which the space between the projection opticalsystem PL and the resist coated on the surface of the substrate P isfilled with the air (gas). Therefore, even when the numerical apertureNA of the projection optical system exceeds 1.0, it is possible toobtain the high image formation performance. It is more effective tomake appropriate combination, for example, with the phase shift maskand/or the oblique incidence illumination method (especially the dipoleillumination method) adjusted to the longitudinal direction of the linepattern. The oblique incidence illumination adjusted to the longitudinaldirection of the line pattern is disclosed, for example, in JapanesePatent Application Laid-open No. 6-188169, content of which isincorporated herein by reference within a range of permission of thedomestic laws and ordinances of the state designated or selected in thisinternational application.

In this embodiment, the lens is attached as the optical element 2 to theend of the projection optical system PL. The lens can be used to adjustthe optical characteristics of the projection optical system PL, forexample, the aberration (for example, spherical aberration and comaticaberration). The optical element 2 may be an optical plate to adjust theoptical characteristic. On the other hand, the optical element 2, whichmakes contact with the liquid 1, may be a plane parallel plate which ischeaper than the lens. When the optical element 2 is the plane parallelplate, it is enough that the plane parallel plate is merely exchangedimmediately before supplying the liquid 1 even when any substance (forexample, any silicon-based organic matter), which deteriorates thetransmittance of the projection optical system PL, the illuminance ofthe exposure light beam EL on the substrate P, and the uniformity of theilluminance distribution, is adhered to the plane parallel plate, forexample, during the transport, the assembling, and/or the adjustment ofthe exposure apparatus EX. An advantage is obtained such that theexchange cost is lowered as compared with the case in which the opticalelement to make contact with the liquid 1 is the lens. That is, thesurface of the optical element to make contact with the liquid 1 isdirtied, for example, due to the adhesion of scattered particlesgenerated from the resist by being irradiated with the exposure lightbeam EL or any impurity contained in the liquid 1. Therefore, it isnecessary to periodically exchange the optical element. However, whenthe optical element is the cheap plane parallel plate, then the cost ofthe exchange part is low as compared with the lens, and it is possibleto shorten the time required for the exchange. Thus, it is possible tosuppress the increase in the maintenance cost (running cost) and thedecrease in the throughput.

When the pressure, which is generated by the flow of the liquid 1, islarge between the substrate P and the optical element disposed at theend of the projection optical system PL, it is also allowable that theoptical element is tightly fixed so that the optical element is notmoved by the pressure, rather than allowing the optical element to beexchangeable.

The liquid 1 is water in this embodiment. However, the liquid 1 may beany liquid other than water. For example, when the light source of theexposure light beam EL is the F₂ laser, the F₂ laser beam is nottransmitted through water. Therefore, in this case, liquids preferablyusable as the liquid 1 may include, for example, a fluorine-based fluidsuch as fluorine-based oil and perfluoropolyether (PFPE) through whichthe F₂ laser beam is transmissive. In this case, the portion to makecontact with the liquid 1 represented by the trap surface 31 issubjected to the liquid-attracting treatment by forming the thin film,for example, with a substance having a molecular structure of smallpolarity including fluorine. Alternatively, other than the above, it isalso possible to use, as the liquid 1, liquids (for example, cedar oil)which have the transmittance with respect to the exposure light beam EL,which have the refractive index as high as possible, and which arestable against the photoresist coated on the surface of the substrate Pand the projection optical system PL. Also in this case, the surfacetreatment is performed depending on the polarity of the liquid 1 to beused.

The projection optical system PL described above is constructed(designed) such that the image formation performance is optimized in theliquid immersion state in which the space on the side of the image planeis filled with the liquid 1 (pure water). However, the projectionoptical system PL may be constructed (designed) such that the desiredimage formation performance is obtained even in the non-liquid immersionstate in which the liquid is absent on the side of the image plane andin the liquid immersion state in which the space on the side of theimage plane is filled with another liquid, by exchanging a part of theoptical element (optical element disposed closely to the substrate P) ofthe projection optical system PL. When the projection optical system PLis constructed as described above, then the exposure apparatus EX can beused in the liquid immersion state, for example, when the large depth offocus DOF is required, and the exposure apparatus EX can be used in thenon-liquid immersion state by exchanging a part of the optical elementwhen the high throughput is required. In such cases, it is desirablethat a spatial image sensor or a wavefront aberration-measuring sensoris arranged on the substrate stage PST in order to measure the imageformation performance after the exchange of the part of the opticalelement. Alternatively, a wavefront aberration-measuring mask may beused. A part of the optical-element may be moved, and/or the wavelengthof the exposure light beam EL may be finely adjusted in order to obtainthe desired image formation performance in each state on the basis ofthe result of the measurement of the image formation performance.Details of the spatial image sensor are disclosed, for example, inJapanese Patent Application Laid-open No. 2002-14005 (corresponding toUnited State Patent Publication No. 2002 0041377), contents of which areincorporated herein by reference within a range of permission of thedomestic laws and ordinances of the state designated or selected in thisinternational application. Details of the wavefront aberration-measuringsensor are disclosed, for example, in International Publication No.02/63664, content of which is incorporated herein by reference within arange of permission of the domestic laws and ordinances of the statedesignated or selected in this international application.

It is desirable that a part of the optical element is exchanged whileallowing the exposure apparatus EX to carry the projection opticalsystem PL. However, the exchange may be performed in a state in whichthe projection optical system PL is detached from the exposure apparatusEX.

The substrate P, which is usable in the respective embodiments describedabove, is not limited to the semiconductor wafer for producing thesemiconductor device. The applicable substrates include, for example,the glass substrate for the display device, the ceramic wafer for thethin film magnetic head, and the master plate (synthetic quartz, siliconwafer) for the mask or the reticle to be used for the exposureapparatus.

As for the exposure apparatus EX, the present invention is alsoapplicable to the scanning type exposure apparatus (scanning stepper)based on the step-and-scan system for performing the scanning exposurefor the pattern of the mask M by synchronously moving the mask M and thesubstrate P as well as the projection exposure apparatus (stepper) basedon the step-and-repeat system for performing the full field exposure forthe pattern of the mask M in a state in which the mask M and thesubstrate P are allowed to stand still, while successively step-movingthe substrate P. The present invention is also applicable to theexposure apparatus based on the step-and-stitch system in which at leasttwo patterns are partially overlaid and transferred on the substrate P.

The present invention is also applicable to a twin-stage type exposureapparatus. The structure and the exposure operation of the twin-stagetype exposure apparatus are disclosed, for example, in Japanese PatentApplication Laid-open Nos. 10-163099 and 10-214783 (corresponding toU.S. Pat. Nos. 6,341,007, 6,400,441, 6,549,269, and 6,590,634),Published Japanese Translation of PCT International Publication forPatent Application No. 2000-505958 (corresponding to U.S. Pat. No.5,969,441), and U.S. Pat. No. 6,208,407, contents of which areincorporated herein by reference within a range of permission of thedomestic laws and ordinances of the state designated or selected in thisinternational application.

As for the type of the exposure apparatus EX, the present invention isnot limited to the exposure apparatus for the semiconductor deviceproduction apparatus for exposing the substrate P with the semiconductordevice pattern. The present invention is also widely applicable, forexample, to the exposure apparatus for producing the liquid crystaldisplay device or for producing the display as well as the exposureapparatus for producing, for example, the thin film magnetic head, theimage pickup device (CCD), the reticle, or the mask.

When the linear motor is used for the substrate stage PST and/or themask stage MST, it is allowable to use any one of those of the airfloating type based on the use of the air bearing and those of themagnetic floating type based on the use of the Lorentz's force or thereactance force. Each of the stages PST, MST may be either of the typein which the movement is effected along the guide or of the guidelesstype in which no guide is provided. An example of the use of the linearmotor for the stage is disclosed in U.S. Pat. Nos. 5,623,853 and5,528,118, contents of which are incorporated herein by referencerespectively within a range of permission of the domestic laws andordinances of the state designated or selected in this internationalapplication.

As for the driving mechanism for each of the stages PST, MST, it is alsoallowable to use a plane motor in which a magnet unit provided withtwo-dimensionally arranged magnets and an armature unit provided withtwo-dimensionally arranged coils are opposed to one another, and each ofthe stages PST, MST is driven by the electromagnetic force. In thisarrangement, any one of the magnet unit and the armature unit isconnected to the stage PST, MST, and the other of the magnet unit andthe armature unit is provided on the side of the movable surface of thestage PST, MST.

The reaction force, which is generated in accordance with the movementof the substrate stage PST, may be mechanically released to the floor(ground) by using a frame member so that the reaction force is nottransmitted to the projection optical system PL. The method for handlingthe reaction force is disclosed in detail, for example, in U.S. Pat. No.5,528,118 (Japanese Patent Application Laid-open No. 8-166475), contentsof which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

The reaction force, which is generated in accordance with the movementof the mask stage MST, may be mechanically released to the floor(ground) by using a frame member so that the reaction force is nottransmitted to the projection optical system PL. The method for handlingthe reaction force is disclosed in detail, for example, in U.S. Pat. No.5,874,820 (Japanese Patent Application Laid-open No. 8-330224), contentsof which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

As described above, the exposure apparatus EX according to theembodiment of the present invention is produced by assembling thevarious subsystems including the respective constitutive elements asdefined in claims so that the predetermined mechanical accuracy, theelectric accuracy, and the optical accuracy are maintained. In order tosecure the various accuracies, adjustments performed before and afterthe assembling include the adjustment for achieving the optical accuracyfor the various optical systems, the adjustment for achieving themechanical accuracy for the various mechanical systems, and theadjustment for achieving the electric accuracy for the various electricsystems. The steps of assembling the various subsystems into theexposure apparatus include, for example, the mechanical connection, thewiring connection of the electric circuits, and the piping connection ofthe air pressure circuits in correlation with the various subsystems. Itgoes without saying that the steps of assembling the respectiveindividual subsystems are performed before performing the steps ofassembling the various subsystems into the exposure apparatus. When thesteps of assembling the various subsystems into the exposure apparatusare completed, the overall adjustment is performed to secure the variousaccuracies as the entire exposure apparatus. It is desirable that theexposure apparatus is produced in a clean room in which, for example,the temperature and the cleanness are managed.

As shown in FIG. 21, the microdevice such as the semiconductor device isproduced by performing, for example, a step 201 of designing thefunction and the performance of the microdevice, a step 202 ofmanufacturing a mask (reticle) based on the designing step, a step 203of producing a substrate as a base material for the device, an exposureprocess step 204 of exposing the substrate with a pattern of the mask byusing the exposure apparatus EX of the embodiment described above, astep 205 of assembling the device (including a dicing step, a bondingstep, and a packaging step), and an inspection step 206.

According to the present invention, when the exposure process isperformed in the state in which the liquid immersion area is formedbetween the projection optical system and the substrate, then it ispossible to stably form the liquid immersion area, it is possible tosatisfactorily recover the liquid, and it is possible to avoid, forexample, the outflow of the liquid to the surroundings. Accordingly, theexposure process can be performed accurately. Therefore, the exposureapparatus of the present invention is extremely useful for the highresolution exposure based on the use of the short wavelength lightsource such as the ArF excimer laser.

1. An exposure apparatus which exposes a substrate by projecting animage of a predetermined pattern through a liquid onto the substrate,the exposure apparatus comprising: a projection optical system whichprojects the image of the pattern onto the substrate; a liquid supplymechanism which has a supply flow passage through which the liquid issupplied onto the substrate; and a liquid recovery mechanism which has arecovery flow passage through which the supplied liquid is recovered,wherein: at least one of the supply flow passage and the recovery flowpassage is formed in a stacked member in which a plurality of platemembers are stacked.
 2. The exposure apparatus according to claim 1,wherein a through-hole, in which a part of the projection optical systemis arranged, is formed to penetrate through the stacked member in athickness direction of the stacked member at a central portion of thestacked member.
 3. The exposure apparatus according to claim 1, whereinat least one of the supply flow passage and the recovery flow passage isformed to penetrate through at least two of the plate members in athickness direction thereof.
 4. A method for producing a device,comprising using the exposure apparatus as defined in claim
 1. 5. Theexposure apparatus according to claim 1, wherein the plate membersinclude a member which has a lower surface, the substrate being oppositeto the lower surface in an exposure operation; and the lower surfaceincludes a trap surface that is capable of capturing liquid.
 6. Theexposure apparatus according to claim 1, wherein the liquid supplymechanism is isolated from the projection optical system in terms ofvibration.
 7. The exposure apparatus according to claim 1, wherein theliquid recovery mechanism is isolated from the projection optical systemin terms of vibration.
 8. The exposure apparatus according to claim 1,wherein the plate members include a first member and a second memberthat are stacked to form the stacked member in which a first surface ofthe first member and a second surface of the second member are oppositeto each other; and at least one of the supply flow passage and therecovery flow passage is formed, between the first and second members,by a groove that is formed in at least one of the first and secondsurfaces.
 9. The exposure apparatus according to claim 8, wherein thegroove is formed in the first surface of the first member that isdisposed above a lower end surface of the projection optical system; andthe liquid is filled in a space between the lower end surface and thesubstrate.
 10. The exposure apparatus according to claim 8, wherein atleast one of the supply flow passage and the recovery flow passageformed between the first and second members is disposed above a lowerend surface of the projection optical system; and the liquid is filledin a space between the lower end surface and the substrate.
 11. Theexposure apparatus according to claim 8, wherein the groove is formed inthe first surface of the first member that is disposed on an upper sideof the second member; and the substrate is moved just below theprojection optical system during exposure.
 12. The exposure apparatusaccording to claim 1, wherein at least one of the supply flow passageand the recovery flow passage penetrates through at least two of theplate members.
 13. The exposure apparatus according to claim 12, whereinthe plate members include a member which has a through-hole in which apart of the projection optical system is arranged.
 14. The exposureapparatus according to claim 12, wherein the plate members include afirst member and a second member that are stacked to form the stackedmember in which a first surface of the first member and a second surfaceof the second member are opposite to each other; and at least one of thesupply flow passage and the recovery flow passage is formed, between thefirst and second members, by a groove that is formed in at least one ofthe first and second surfaces.
 15. The exposure apparatus according toclaim 12, wherein the liquid recovery mechanism includes a recovery portannularly disposed around a projection area onto which the image of thepattern is projected during exposure.
 16. The exposure apparatusaccording to claim 15, wherein the recovery port includes a plurality ofopenings.
 17. The exposure apparatus according to claim 1, wherein theplate members include a member which has a through-hole in which a partof the projection optical system is arranged.
 18. The exposure apparatusaccording to claim 17, wherein the plate members include a first memberand a second member that are stacked to form the stacked member in whicha first surface of the first member and a second surface of the secondmember are opposite to each other; and at least one of the supply flowpassage and the recovery flow passage is formed, between the first andsecond members, by a groove that is formed in at least one of the firstand second surfaces.
 19. The exposure apparatus according to claim 17,wherein the liquid recovery mechanism includes a recovery port annularlydisposed around a projection area onto which the image of the pattern isprojected during exposure.
 20. The exposure apparatus according to claim19, wherein the recovery port includes a plurality of openings.
 21. Theexposure apparatus according to claim 1, wherein the liquid recoverymechanism includes a recovery port annularly disposed around aprojection area onto which the image of the pattern is projected duringexposure.
 22. The exposure apparatus according to claim 21, wherein therecovery port includes a plurality of openings.
 23. The exposureapparatus according to claim 21, wherein the plate members include afirst member and a second member that are stacked to form the stackedmember in which a first surface of the first member and a second surfaceof the second member are opposite to each other; and at least one of thesupply flow passage and the recovery flow passage is formed, between thefirst and second members, by a groove that is formed in at least one ofthe first and second surfaces.